15 th ICAAR ABSTRACTS OF THE PROCEEDINGS

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2 15 th ICAAR ABSTRACTS OF THE PROCEEDINGS Haroldo de Mayo Bernardes & Nicole Pagan Hasparyk (Editors) Brazil, July 2016

3 Introduction The International Conference on Alkali-Aggregate Reaction in Concrete (ICAAR) aims to join the scientists and engineers dedicated to deleterious alkali-aggregate reaction in concrete The first paper on this pathology of concrete in Brazil was published by Heraldo de Souza Gitahy in 1963, around 23 years after the first paper worldwide. Roy Carlson, a Californian consulting engineer, was participating of this research team, aiming the construction of Jupiá dam. There were 11 years before the first ICAAR be occurred. Now we are pleased to welcome the 15 th ICAAR, to be held at the Maksoud Plaza Hotel in São Paulo, Brazil, on July of Since the 14th ICAAR, when our delegation received with great honor the confidence by the International AAR Committee to organize the next event edition, this conference received important support and contributions from the reviewers, and from partners for organization and sponsoring. We are thankful to all involved in this very rich process. It was a great challenge because the general conditions now are not as good as at We hope to provide and improve communication among participants, specialists already dedicated to AAR or interested on it. On the last month of preparation, delegates from 18 countries had registered to the conference, expecting the oral and poster sessions, with over one hundred of peer-reviewed full papers, in its majority to be part of the conference Proceedings. The main themes include testing procedures, methods of modelling and the association with other expansive processes. In addition, we have arranged two technical tours. The first one is a 3-day pre-conference tour to Paulo Afonso Hydro Power Plant, to visit its concrete structures suffering from AAR and the wonderful canyons of the São Francisco River. The second is a 1-day post-conference technical visit to Jaguari dam, 1 hour by bus far from São Paulo city, shorter but in a very beautiful region too. We look forward to offer you a wonderful technical conference, as well as an unforgettable experience in the financial heart of South America, São Paulo, and its enthusiastic cultural and gastronomic life. São Paulo, July 2016 Haroldo de Mayo Bernardes, Chairman

4 Foreword The Organizing and Scientific Committees of the 15 th International Conference on Alkali-Aggregate Reaction in Concrete (ICAAR) welcome all the participants and hope that you to feel at home in São Paulo, Brazil. We are very much honored to host such an important event in Brazil, and look forward to offer you a wonderful technical Conference, as well as an unforgettable experience in São Paulo. The first ICAAR was organized in Koge, Denmark in 1974 with the presence of only four countries. It was then followed by ICAARs organized in 1975, 1976, 1978, 1981, 1983, 1986, 1989, 1992, 1996, 2000, 2004, 2008, 2012 and finally The next Conference will be held in The first meetings were mainly focused on the identification of reactive aggregates and case studies. Unfortunately, it has turned out that the number of countries presenting AARrelated problems has increased and so does the number of constructions suffering from the problem such as: dams, hydropower plants, nuclear power plants, foundations of transmission lines, foundations of residential, commercial and industrial buildings, bridges, overpasses, road pavements, etc. Overall, there is fair enough knowledge in the technical society for mitigating/avoiding AAR occurrence in the field, before concrete s placement. However, once AAR is already developed, a full understanding on how to deal with the problem (i.e. selection of rehabilitation techniques, management procedures, modeling, prediction and prognosis of the problem, structural implications, etc.) is still lacking, even after all the conferences and technical meetings held in the past. Researchers are still deeply studying a number of fundamental aspects of such complex chemical reaction and this 15 th ICAAR will be indeed an important discussion forum related to: tests aimed to correctly identify and mitigate potentially reactive aggregates, importance of alkali release from aggregates, the influence of other mechanisms inducing substantial expansions in concrete such as the delayed ettringite formation (DEF), methods to predict the future behavior of AAR-damaged structures, repairs and remedial measures to restrain expansions and improve durability and long term behaviour of affected structures, among many other items. Moreover, one important topic that should be addressed is the quantification of the expansion level attained by AARaffected structures. We are sure that this Conference will provide to all students and professionals involved a very good opportunity to devise solutions to approach the severe problems caused by AAR. We hope that the technical discussions held in São Paulo will widespread afterwards worldwide and the Organizing and the Scientific Committees will do their best to disseminate not only the papers presented here but also the conclusions reached during the 15 th ICAAR. Selmo Chapira Kuperman Vice-Chairman

5 Preface The International Conference on Alkali-Aggregate Reaction in Concrete (ICAAR) is one of the most important conferences dealing with durability-related issues in concrete, particularly alkali-aggregate reaction (AAR) and related mechanisms. The 15 th ICAAR Proceedings include manuscripts submitted and approved from a number of countries (about 20!!) all around the world! The Proceedings consist of a pen drive containing an app with a large database. It enables searching by manuscripts titles, authors and keywords. You may also access and print individual PDF papers and obtain further information related to this conference. Each manuscript published was previously and carefully peer-reviewed by an international board of reviewers selected worldwide. From about 200 abstracts received, 153 full manuscripts were submitted to the conference, among which 146 final versions were inserted in these Proceedings. This procedure has generated more than 350 reviews, which showed to be a challenging task indeed! The majority of authors have addressed the major comments from the reviewers, thus being accepted for publication; only 3 review invitations were declined, 3 manuscripts were unfortunately rejected and 1 author withdrew his paper. We would really like to thank each member of the International Board of Reviewers for their effort and important collaboration in the reviewing process. Likewise, we also thank Dr. Selmo Chapira Kuperman for his continuous and indispensable contribution to the scientific and organizing committees over the last four years of dedication. The 10 themes addressed in this conference were: Mechanisms of AAR Factors affecting AAR Testing for potential AAR Preventive measures Diagnosis and assessment Cases of deterioration Structural effects of AAR Monitoring and modeling Repair and remedial measures Concrete distressed due to coupled AAR and DEF mechanisms

6 Moreover, 9 worldwide experts within the different themes illustrated above were invited for Keynote Lectures, as presented hereafter: AAR Petrographic Overview and Development of a New Petrographic Atlas Isabel Fernandes (University of Lisbon / ICT) - PORTUGAL Current Developments in Research on Alkali Aggregate Reactions & RILEM Overview Børge Johannes Wigum - NORCEM (HeidelbergCement Group / Chairman: RILEM TC 258-AAA) - NORWAY ACI / ASTM Overview Jason H. Ideker (Oregon State University) USA Diagnosis & Prognosis of AAR Affected Concrete Structures Benoît Fournier (Laval University) & Leandro Sanchez (University of Ottawa) - CANADA AAR Modeling and Structural Implications Stéphane Multon (INSA) & Etienne Grimal (EDF-DPIH) FRANCE AAR in Brazil Selmo Kuperman (DESEK) & Nicole Pagan Hasparyk (ELETROBRAS Furnas) - BRAZIL ICAAR consists of a unique opportunity to network with a number of worldwide experts as well as to participate in the dissemination of current AAR researches and practical cases which contribute to the enhancement of knowledge in the area. We wish the continuation of the ICAAR Conferences for the years to come and we hope you appreciate the 15 th ICAAR in São Paulo-Brazil and also the Conference Proceedings! São Paulo, July 2016 Nicole Pagan Hasparyk Leandro Sanchez Coordinators of the 15 th ICAAR Scientific Committee

7 15 th ICAAR BRAZIL NOTICE The papers contained in this 15 th ICAAR Proceedings volume have been refereed by international peers, and are considered to constitute the latest information available in the relevant fields. Editors do not accept responsibility nor liability for errors or any consequences arising from the use of information contained herein. This Proceedings volume is intended as a collection of scientific and engineering information only. Responsibility for final determination of the suitability of any information, procedure or products, for use contemplated by any user, and the manner of that use is solely of the user. When implementation is considered, with respect to all equipment and procedures, expert advice should be obtained at all times. COPYRIGHT 15 th ICAAR does not hold the copyright from authors for the approved and published papers in the Proceedings. No part of this publication may be reproduced by any means, or transmitted in any form without prior written permission from the authors of each manuscript. ADDITIONAL COPIES For up to date information on availability, contact the: Library of the Faculdade de Engenharia de Ilha Solteira (FEIS/UNESP): Av. Brasil, 56 CEP Ilha Solteira - SP - Brazil gd@feis.unesp.br

8 Committees - 15 th ICAAR - BRAZIL Chairman Haroldo de Mayo Bernardes Vice-Chairman Selmo Chapira Kuperman Scientific Committee Nicole Pagan Hasparyk (President) Leandro Sanchez (Vice-President) Arnaldo Forti Battagin Claudio Sbrighi Neto Haroldo de Mayo Bernardes Selmo Chapira Kuperman Silvia Regina S. da Silva Vieira Board of Reviewers of the Scientific Committee Ahmad Shayan, Dr (Australia) Alberto Jorge T Cavalcanti, Eng (Brazil) Ana Lívia Zeitune de P. Silveira, MSc (Brazil) António Santos Silva, Dr (Portugal) Arnaldo Forti Battagin, Dr (Brazil) Bård Pedersen, Dr (Norway) Benoit Fournier, Dr (Canada) Bent Grelk, Dr (Denmark) Børge J Wigum, Dr (Iceland) Bruno Godart, Dr (France) Chris Rogers, MSc (Canada) Cláudio Sbrighi, Dr (Brazil) Doug Hooton, Dr (Canada) Eric Garcia-Diaz, Dr (France) Eric Giannini, Dr (USA) Farshad Rajabipour, Dr (USA) Flávio Salles, Eng (Brazil) Francesco Amberg, MSc (Switzerland) Francieli Tiecher, Dr (Brazil) Fred H Shrimer, MSc (Canada) Harald Justnes, Dr (Norway) Haroldo de Mayo Bernardes, Dr (Brazil) Heloisa Helena A B Silva, MSc (Brazil) Isabel Fernandes, Dr (Portugal) Jan Lindgård, Dr (Norway) Jason Ideker, Dr (USA) Jonathan Wood, Dr (UK) Josée Duchesne, Dr (Canada) Klaus-Jürgen Hünger, Dr (Germany) Kleber Franke Portella, Dr (Brazil) Leandro Sanchez, Dr (Canada) Luciana dos Anjos Farias, MSc (Brazil) Maarten A T M Broekmans, Dr (Netherlands) Martin Cyr, Dr (France) Martin Noël, Dr (Canada) Nicole Pagan Hasparyk, Dr (Brazil) Patrícia Neves Silva, MSc (Brazil) Paulo Monteiro, Dr (USA) Renaud-Pierre Martin, Dr (France) Sandro Marden Torres, Dr (Brazil) Selmo Chapira Kuperman, Dr (Brazil) Silvia Regina S da Silva Vieira, Dr (Brazil) Silvina Marfil, Dr (Argentina) Stéphane Multon, Dr (France) Tetsuya Katayama, Dr (Japan) Thano Drimalas, Dr (USA) Tibério Andrade, MSc (Brazil) Victor Saouma, Dr (USA) Vladimir Gocevski, Dr (Canada)

9 Committees - 15 th ICAAR - BRAZIL Organizing Committee Alberto Jorge C. T. Cavalcanti Ana Livia Zeitune de Paula Silveira Arnaldo Forti Battagin Claudio Sbrighi Neto Eduardo Fairbairn Flávio Moreira Salles Francieli Tiecher Haroldo de Mayo Bernardes Hugo Rodrigues Leandro Sanchez Luiz Prado Vieira Júnior Nicole Pagan Hasparyk Patricia Neves Silva Selmo Chapira Kuperman Silvia Regina S. da Silva Vieira Tiberio Andrade Túlio Nogueira Bittencourt Yushiro Kihara ICAAR International Committee Silvina Marfil (Argentina) Ahmad Shayan (Australia) Stefan Krispel (Austria) Nemat Tenoutasse (Belgium) Selmo Kuperman (Brazil) Benoit Fournier (Canada) Deng Min (China) Mette Geiker (Denmark) Bruno Godart (France) Christoph Müller (Germany) Wen Hong-Xing (Hong Kong) Gísli Guðmundsson (represented by Borge J Wigum - Iceland) Ajoy K Mullick (India) Giampiero Barisone (Italy) Mario Berra (Italy) Toyoaki Miyagawa (Japan) Maarten A T M Broekmans (Netherlands) Viggo Jensen (Norway) Isabel Fernandes (Portugal) Kyong-Ku Yun (South Korea) Esperanza Menendez Mendez (Spain) Christine Merz (Switzerland) Özge Andiç-Çakir (Turkey) Ian Sims (UK) Kevin Folliard (USA)

10 TABLE OF CONTENTS 15 th ICAAR ABSTRACTS Themes 1. Mechanisms of AAR 2. Factors affecting AAR 3. Testing for potential AAR 4. Preventive measures 5. Diagnosis and assessment 6. Cases of deterioration 7. Structural effects of AAR 8. Monitoring and modeling 9. Repair and remedial measures 10. Concrete distressed due to coupled AAR and DEF mechanisms / DEF

11 Table of Contents THEME 01 - MECHANISMS OF AAR USE OF SCMS ON ACR-AFFECTED CONCRETE: EXPANSION AND DAMAGE EVALUATION THROUGH THE DAMAGE RATING INDEX 20 THE INFLUENCE OF ASR GELS COMPOSITION ON THEIR SWELLING PROPERTIES 21 ALKALI AGGREGATE REACTION IN ICELAND RESULTS FROM LABORATORY TESTING COMPARED TO FIELD EXPOSURE SITE 22 EFFECT OF ALKALI LEACHING ON EXPANSION TESTS IN LABORATORY 23 MICROSTRUCTURAL AND CHEMICAL STUDY ON AN EXPANSIVE DOLOSTONE FROM ARGENTINA 24 INFLUENCE OF AGGREGATE PARTICLE SIZE ON THE ALKALI-SILICA REACTION - A LITERATURE REVIEW 25 INFLUENCE OF SODIUM CHLORIDE ON ASR IN HIGHWAY PAVEMENT CONCRETE 26 GLOBALISING AAR: 26 YEARS OF RILEM ENDEAVOUR 27 A WORLDWIDE VIEW OF AAR: UPDATING SWAMY 28 INFLUENCE OF AGGREGATE SIZE ON THE DAMAGE POTENTIAL OF ALKALI-SILICA REACTION 29 ALKALI SILICA REACTION IN CONCRETE FOUNDATIONS IN THAILAND 30 EFFECTS OF EXPANSION BEHAVIOR OF ASR-AFFECTED CONCRETE IN ATMOSPHERES WITH VARIOUS VALUES OF RELATIVE HUMIDITY ON SURFACE CRACKING 31 INVESTIGATION OF REACTIVITY OF A DOLOMITIC AGGREGATE FROM AUSTRALIA 32 THE INFLUENCE OF LITHIUM ON THE STRUCTURE OF ASR PRODUCTS IN CONCRETE 33 ALKALI SILICA REACTION MITIGATING PROPERTIES OF TERNARY BLENDED CEMENT WITH CALCINED CLAY AND LIMESTONE 34 ALKALI-AGGREGATE REACTION IN RECYCLED CONCRETE WITH AGGREGATES QUALIFIED AS REACTIVES BY THE ASTM C 1260 METHOD 35 THE ROLE OF ALKALI-DOLOMITE REACTION IN DETERIORATION OF AN AIRPORT PAVEMENT 36 EXPANSIVE MECHANISM OF RILEM AAR-5 CONCRETE MICROBARS WITH DOLOSTONES 37 BEHAVIOURS OF REACTIVE SILICA AND DOLOMITE IN TETRAMETHYL AMMONIUM HYDROXIDE SOLUTIONS 38 EVALUATION OF THE AVAILABLE ALKALI CONTENT IN CONCRETE THROUGH A MODIFIED HOT-WATER EXTRACTION METHOD 39

12 Table of Contents THEME 02 - FACTORS AFFECTING AAR TIME-DEPENDENT COEFFICIENT OF THERMAL EXPANSION OF AN ALKALI-SENSITIVE ROCK IN ALKALINE SOLUTION 41 SURFACE COATING OF SILICEOUS PARTS OF AGGREGATE GRAINS BY ALUMINA CONTAINING SCM`S IN ALKALINE SOLUTIONS 42 THE INFLUENCE OF SUPPLEMENTARY CEMENTING MATERIALS ON THE DISSOLUTION OF AGGREGATES IN ALKALINE SOLUTIONS 43 REVIEW OF METHODS TO DETERMINE THE PH AND THE FREE ALKALI CONTENT OF THE PORE SOLUTION IN CONCRETE 44 ASSESSMENT OF THE ALKALI-REACTIVITY POTENTIAL OF SEDIMENTARY ROCKS 45 STUDY ON THE FACTORS AFFECTING ALKALIS RELEASE FROM AGGREGATES INTO ASR 46 ANALYSIS OF CORRELATION BETWEEN THE EXPANSION RATE AND THE INDEX OF REACTIVITY DETERMINED BY PETROGRAPHY 47 EARLY ASSESSMENT OF ALKALI-SILICA REACTION IN ALKALI-ACTIVATED FLY ASH CONCRETE SUBJECTED TO THE CONCRETE PRISM TEST (ASTM C1293) 48 FIELD AND LABORATORY EXAMINATIONS OF AN ASR-AFFECTED BRIDGE VARIATION IN CRACK EXTENT AND WATER CONTENT 49 INFLUENCE OF SIMULTANEOUS CYCLIC LOADING AND EXTERNAL ALKALI SUPPLY ON THE ALKALI-SILICA REACTION IN CONCRETE PAVEMENTS 50 ASR - PERFORMANCE TESTING: MAIN FINDINGS IN THE NORWEGIAN COIN PROJECT 51 THEME 03 - TESTING FOR POTENTIAL AAR MODIFICATIONS OF THE CONCRETE PRISM TEST WHEN TESTING LOW-ALKALI CEMENT WITH SCM SYSTEMS FOR MITIGATION OF ALKALI-SILICA REACTION 53 TRACKING ALKALI MIGRATION AND LEACHING IN THE AUTOCLAVED CONCRETE PRISM TEST 54 INTER-LABORATORY COMPARISON OF EXPANSIONS FROM THE AUTOCLAVED CONCRETE PRISM TEST 55 POST-MORTEM REVIEW OF CONCRETE PRISM TEST SPECIMENS: PETROGRAPHIC OBSERVATIONS 56 IMPROVING THE RELIABILITY OF THE ASTM C1260 ACCELERATAED MORTAR BAR TEST 57 DEVELOPING A RAPID CONCRETE TEST TO ASSESS ALKALI-SILICA REACTION 58

13 Table of Contents RILEM TECHNICAL COMMITTEES (TCS) PAST AND PRESENT. TC 258-AAA: AVOIDING ALKALI AGGREGATE REACTION (AAR) IN CONCRETE PERFORMANCE BASED CONCEPT ( ) 59 ALKALI SILICA REACTION IN AGGREGATES DERIVED FROM THE VALORISATION OF WASTES FROM THE AGATE MINING 60 IMPORTANCE OF ALKALI-WRAPPING IN CONCRETE PRISM TESTS 61 RE-EVALUATION OF TESTING PARAMETERS IN THE ACCELERATED MORTAR BAR TEST 62 CAN METAKAOLIN-BASED GEOPOLYMERS SUFFER FROM ALKALI SILICA REACTION? 63 THE USE OF ACCELERATED MORTAR BAR EXPANSION RATES AND REACTION KINETIC MODEL IN DETECTING ALKALI-SILICA REACTIVE AGGREGATES 64 AN ACCELERATED AND MORE ACCURATE TEST METHOD TO ASTM C1293: THE CONCRETE CYLINDER TEST 65 PORTUGUESE EXPERIENCE IN ASR AGGREGATE ASSESSMENT 66 ASR IMPACT ON CONCRETE WITH RECYCLED AGGREGATES 67 TO BE OR NOT TO BE... ALKALI-REACTIVE. A CHALLENGE FOR THE PETROGRAPHIC METHOD 68 ALKALI RELEASE OF AGGREGATES. EFFECTIVENESS OF DIFFERENT SOLUTIONS AND CONDITIONS OF TEST 69 MANAGING ALKALI-AGGREGATE REACTIVITY: NORTH AMERICAN APPROACH 70 POTENTIAL OF NON-DESTRUCTIVE AND MICRO ANALYTICAL TECHNIQUES APPLIED TO THE STUDY OF DAMAGE ASSESSMENT AND MITIGATION IN ASR PRONE STRUCTURES 71 ELEMENTAL AND PHASE CHARACTERIZATION OF COARSE AGGREGATES COMMERCIALLY AVAILABLE FOR CONCRETE PRODUCTION IN THE BRAZILIAN NORTHEAST 72 ALKALI SILICA REACTION IN CONCRETE WITH GRANITE - LABORATORY TESTS AND REAL SERVICE CONDITIONS 73 THE ALKALI-SILICA REACTIVITY OF ANDESITIC RIVER AGGREGATES AND ASR MITIGATION EFFECT BY USING FINE FLY ASHES 74 EXACT EFFECTS OF TEMPERATURE INCREASE AND ALKALI BOOSTING IN CONCRETE PRISM TESTS WITH ALKALI WRAPPING 75 CAN LIGHT WEIGHT AGGREGATE (LWA) LEAD TO HARMFUL ASR IN THE FIELD? 76 EVALUATION OF ALKALI-SILICA REACTION POTENTIAL OF MARGINAL AGGREGATES USING MINIATURE CONCRETE PRISM TEST (MCPT) 77

14 Table of Contents A ROBUST TESTING PROTOCOL FOR THE ASSESSMENT OF ASR REACTIVITY OF CONCRETE 78 ASSESSMENT OF EXPANSION LEVELS OF VARIOUS MIXTURES WITH MULTIPLE EXPOSURE CONDITIONS (CONSECUTIVE FREEZE-THAW AND ASR CYCLES) 79 THE STUDY OF THE AZOREAN VOLCANIC AGGREGATES FROM THE POINT OF VIEW OF ALKALI SILICA REACTION. 80 EVALUATION OF THE DELETERIOUS CHARACTER OF SILICEOUS AGGREGATES INCORPORATING SULFIDE MINERALS 81 THEME 04 - PREVENTIVE MEASURES EXPANSION OF CONCRETE CONTAINING REACTIVE RECLAIMED CONCRETE AGGREGATES OF DIFFERENT REACTIVITY AND COMPOSITION 83 ALKALI-CARBONATE REACTION: MECHANISM AND EFFECTS OF CEMENT ALKALI AND SUPPLEMENTARY CEMENTING MATERIALS 84 AN EXAMINATION OF AAR MITIGATION MEASURES USING FLY ASH 85 STUDY ON ASR EXPANSION AND ITS SUPPRESSING MEASURES OF SELF-COMPACTING CONCRETE USING SEA WATER 86 POTENTIAL OF METAKAOLIN IN MITIGATING EXPANSIONS OF ASR IN ACCELERATED TESTS 87 INFLUENCE OF SUGARCANE BAGASSE ASH IN THE EXPANSIONS OF MORTARS AFFECTED BY ALKALI-SILICA REACTION 88 FLY ASH TO PREVENT ASR WITH SLOWLY-REACTIVE AGGREGATES IN PORTUGAL 89 A REVIEW ON USING CALCINED CLAYS TO MITIGATE ALKALI-SILICA REACTION 90 OBSERVATIONS ON USING EXPANDED CLAY TO CONTROL EXPANSION CAUSED BY ALKALI- SILICA REACTION 91 EFFECT OF THE USE OF AAC IN MITIGATING THE ALKALI-AGGREGATE REACTION 92 THRESHOLD EFFECT IN ALKALI-SILICA REACTION INHIBITION ON MICRO-MORTARS AND MORTARS WITH LiOH 93 INFLUENCE OF ALKALI CONTENT OF CEMENT ON MECHANICAL AND DURABILITY PERFORMANCE OF UHPC 94 EFFECTIVENESS OF ALKALI-ACTIVATED SLAG BASED BINDERS AND FLY-ASH BASED GEOPOLYMERS AGAINST ALKALI SILICA REACTION (ASR) 95

15 Table of Contents INFLUENCE OF SUPERPLASTICIZERS ADMIXTURES IN THE ALKALI-SILICA REACTION 96 COMPARATIVE FIELD AND LABORATORY INVESTIGATIONS ON THE USE OF SUPPLEMENTARY CEMENTING MATERIALS (SCMS) TO CONTROL ALKALI-SILICA REACTION (ASR) IN CONCRETE 97 THEME 05 - DIAGNOSIS AND ASSESSMENT CREEP BEHAVIOUR OF ALKALI-SILICA REACTION DAMAGED CONCRETE WITH SLOW- REACTING AGGREGATES 99 THOROUGH EVALUATION OF BRIDGE COLUMNS AFFECTED BY ALKALI-SILICA REACTION (ASR) 100 THE USE OF THE DAMAGE RATING INDEX (DRI) FOR THE CONDITION ASSESSMENT OF AGING DISTRESSED CONCRETE 101 THOROUGH CHARACTERIZATION OF CONCRETE DAMAGE CAUSED BY AAR THROUGH THE USE OF A MULTI-LEVEL APPROACH 102 DEVELOPMENT AND TESTING OF NDE MOCKUP SPECIMENS WITH ASR 103 DIAGNOSIS OF AAR AND DEF: COMPARISON OF RESIDUAL EXPANSION, STIFFNESS DAMAGE TEST AND DAMAGE RATING INDEX 104 INVESTIGATION AND ASSESSMENT OF ALKALI AGGREGATE REACTION (AAR) IN THE PIRAPORA DAM 105 DEVELOPMENT OF AN ELECTROCHEMICAL MIGRATION CELL FOR LITHIUM IMPREGNATION LABORATORY ASSESSMENT 106 APPLICATION OF PROGNOSIS AND DIAGNOSIS TECHNIQUES OF ASR FOR A HISTORIC STRUCTURE 107 ASSESSMENT OF SEVERELY ASR DAMAGED BRIDGES: FROM DIAGNOSIS TO STRUCTURAL EFFECTS 108 IMAGE ANALYSIS OF ALKALI-AGGREGATE GEL IN CONCRETE PRISM TEST WITH ALKALI-WRAPPING 109 AGING MANAGEMENT OF NUCLEAR POWER PLANTS IN JAPAN WITH RESPECT TO THE ALKALI SILICA REACTION 110 EVALUATION OF THE CONCRETE PRISM AND THE ACCELERATED MORTAR BAR TESTS FOR ASSESSING THE POTENTIAL ALKALI-SILICA REACTIVITY OF RECYCLED CONCRETE AGGREGATES 111 COMPREHENSIVE ASSESSMENT OF THE CAHORA BASSA DAM S CONCRETE SWELLING PROCESS 112

16 Table of Contents CHARACTERISTIC BEHAVIOUR OF THE PORTUGUESE LARGE CONCRETE DAMS BUILT WITH GRANITE AGGREGATES AND AFFECTED BY ASR YEAR MANAGEMENT OF 253 BRIDGES POTENTIALLY AFFECTED BY AAR YEAR RESULTS OF AN IN-SITU MONITORING STUDY OF LARGE CONCRETE ELECTRICAL TOWER FOUNDATIONS AFFECTED BY ALKALI-SILICA REACTION (ASR) 115 COMBINATION OF NUMERICAL MODELLING AND LABORATORY TESTING TO ASSESS THE ALKALI-SILICA REACTION (ASR) AT RAPIDES-DES-ÎLES HYDROELECTRIC POWER PLANT, QUÉBEC, CANADA 116 SEMI-QUANTITATIVE CONDITION ASSESSMENT OF CONCRETE DISTRESS THROUGH THE DAMAGE RATING INDEX 117 DESIGN FOR WIDENING OF EXISTING BRIDGE PIERS AFFECTED BY ALKALI-SILICA REACTION (ASR) 118 LABORATORY METHODOLOGY FOR EVALUATING THE EXPANSION PROCESS IN STRUCTURES AFFECTED BY AAR 119 DIGITAL IMAGE ANALYSIS OF DETERIORATED CONCRETE TREATED WITH URANYL ACETATE FOR DETECTION OF ALKALI AGGREGATE REACTION 120 THEME 06 - CASES OF DETERIORATION EVALUATION OF THE DEGREE OF DAMAGE CAUSED BY ALKALI-SILICA REACTION IN A HIGHWAY PAVEMENT: A CASE STUDY 122 DIAGNOSIS OF ALKALI-SILICA REACTION IN AIRPORT PAVEMENT IN JAPAN 123 REVISITING AN HISTORIC CASE STUDY: MONITORING AND ASSESSMENT OF ASR IN A DECOMMISSIONED LOCK STRUCTURE 124 REMEDIATION STRATEGIES INTENDED FOR THE RECONSTRUCTION OF THE ASR-INDUCED MACTAQUAC DAM 125 ASSESMENT OF ALKALI-SILICA REACTION IN SOME CONCRETES FROM BRAZILIAN HYDROELECTRIC POWER PLANTS 126 OCCURRENCE OF LATE-EXPANSIVE ASR IN A GRANITOID ROCK WITH MICROGRAPHIC TEXTURE, HOKURIKU REGION, JAPAN 127 OLDEST EXAMPLE OF ALKALI-SILICA REACTION IN JAPAN TOKYO BAY SEA FORTS NO. 2 AND NO. 3, CONSTRUCTED YEARS AGO 128 DIAGNOSIS OF ASR IN AIRPORT PAVEMENTS IN JAPAN EARLY-EXPANSIVE SAND AGGREGATE MISSED BY CONVENTIONAL TEST 129

17 Table of Contents ASR FOUND IN THAILAND AND TROPICAL REGIONS OF SOUTHEAST ASIA 130 DIAGNOSIS OF ALKALI SILICA REACTION 131 THEME 07 - STRUCTURAL EFFECTS OF AAR PERFORMANCE EVALUATION OF THICK CONCRETE SLABS AFFECTED BY ALKALI-SILICA REACTION (ASR) PART II : STRUCTURAL ASPECTS 133 PERFORMANCE EVALUATION OF THICK CONCRETE SLABS AFFECTED BY ALKALI-SILICA REACTION (ASR) : PART 1 : MATERIAL ASPECTS 134 STRUCTURAL IMPLICATIONS OF INTERNAL SWELLING REACTIONS IN CONCRETE: A REVIEW 135 STUDY OF BOND BETWEEN EPOXY, STEEL REINFORCING BARS AND CONCRETE AFFECTED BY ALKALI-SILICA REACTION 136 SHEAR CAPACITY OF ASR DAMAGED STRUCTURES IN-DEPTH ANALYSIS OF SOME IN-SITU SHEAR TESTS ON BRIDGE SLABS 137 EXPANSION SLOT CUTTING TO COUNTERACT ALKALI AGREGGATE REACTION AT PEDRA DAM 138 ROLE OF PRE-CRACK FORMATION AND ALKALI SILICA REACTION ON CONCRETE 139 COMPUTATIONAL STUDY ON STRUCTURAL PERFORMANCE OF ASR DAMAGED RC MEMBERS 140 EXPERIMENTAL AND ANALYTICAL STUDIES ON FLEXURAL BEHAVIOR OF POST-TENSIONED CONCRETE BEAM SPECIMEN DETERIORATED BY ALKALI-SILICA REACTION (ASR) 141 IMPACT OF MULTI-AXIAL STRESSES ON ASR EXPANSION 142 SHEAR CAPACITY OF LARGE-SCALE RC BEAMS AFFECTED BY ASR 143 LONG-TERM DETERIORATION OF QUASI-ACTUAL SCALE PRESTRESSED CONCRETE BEAM DUE TO ALKALI-SILICA REACTION 144 THEME 08 - MONITORING AND MODELING NUMERICAL STUDY ON RESTRAINMENT OF REINFORCED CONCRETE DUE TO AAR EXPANSION 146 INFLUENCE OF CREEP AND STRESS STATES ON ALKALI-SILICA REACTION INDUCED- EXPANSION OF CONCRETE UNDER RESTRAINT 147 MODELLING OF EVOLUTION OF TRANSFER PROPERTIES DUE TO EXPANSION OF CONCRETE INDUCED BY INTERNAL SWELLING REACTION 148

18 Table of Contents CORRELATION BETWEEN LABORATORY EXPANSION AND FIELD EXPANSION OF CONCRETE: PREDICTION BASED ON MODIFIED CONCRETE EXPANSION TEST 149 A MICROMECHANICAL MODEL OF ASR ANISOTROPY. APPLICATION TO AFFECTED COLUMNS 150 STUDY OF THE STRUCTURAL BEHAVIOR OF PIRAPORA DAM AFFECTED BY ALKALI-AGGREGATE REACTION 151 DEVELOPMENT OF A PRELIMINARY GENERAL MODEL OF OCCURRENCE OF ALKALI SILICA AGGREGATE REACTION IN CONCRETE STRUCTURES 152 NUMERICAL MODEL APPLIED TO THE REASSESSMENT OF THE SERVICEABILITY AND SAFETY OF AAR-AFFECTED POWER-PLANT 153 CHEMO-HYGRAL AND PORO-MECHANICAL MODELING FOR ASR AND STRUCTURAL PERFORMANCE ASSESSMENT OF RC BRIDGE DECKS 154 QUANTUM PARTICLE SWARM OPTIMIZATION APPLIED TO AUTOMATED CRACK PATTERN ASSESSMENT OF BACKSCATTERED ELECTRON IMAGE IN CEMENTITIOUS SYSTEMS 155 MODELING THE ORTHOTROPIC EXPANSION INDUCED BY ALKALI-AGGREGATE REACTION: METHODOLOGICAL REVIEW AND PRACTICAL APPLICATION 156 MODELLING OF ALKALI-AGGREGATE REACTION IN CONCRETE PILE CAPS STRUCTURES 157 STRUCTURAL EFFECTS OF AAR ON THE JAGUARI HYDROPOWERPLANT WATER INTAKE 158 THEME 09 - REPAIR AND REMEDIAL MEASURES EFFECT OF CFRP WRAPPING TIME ON EXPANSION DEVELOPMENT AND LOAD CAPACITY OF CIRCULAR CONCRETE COLUMNS AFFECTED BY ALKALI-AGGREGATE REACTION 160 SPILLWAYS AFFECTED BY ALKALI-AGGREGATE REACTION : TWO CASE STUDIES FROM HYDRO- QUEBEC 161 MAINTENANCE AND REPAIRS ON THE WATER INTAKE OF JAGUARI HYDROPOWERPLANT AFFECTED BY AAR. 162 COATINGS AND SEALERS FOR MITIGATION OF ALKALI-SILICA REACTION AND/OR DELAYED ETTRINGITE FORMATION 163 MEASURING RELATIVE HUMIDITY IN CONCRETE PAVEMENTS AS A METHOD TO ASSESS ASR MITIGATION MEASURES 164 MITIGATION OF ALKALI-SILICA REACTION IN CONCRETE PAVEMENTS BY SILANE TREATMENT 165 STUDY OF SILANE COMPOSITIONS TO MITIGATE ALKALI-SILICA REACTION 166

19 Table of Contents THE REINFORCEMENT OF AN ASR AFFECTED INTAKE TOWER USING POST-TENSIONED TENDONS 167 THEME 10 - CONCRETE DISTRESSED DUE TO COUPLED AAR AND DEF MECHANISMS / DEF COEXISTENCE OF ASR AND DEF IN A PRECAST PRE-STRESSED CONCRETE ELEMENT IN CHINA 169 THE EFFECTS OF DELAYED ETTRINGITE FORMATION ON THE EXPANSION OF A MASSIVE BRIDGE PIER AND A PRECAST PRESTRESSED CONCRETE BEAM OF A BRIDGE 170 EXPERIMENTAL STUDY OF THE INFLUENCE OF LATE HEAT TREATMENT ON THE RISK OF EXPANSION ASSOCIATED WITH DELAYED ETTRINGITE FORMATION 171 EFFECT OF TEMPERATURE AND CURING DURATION OF EARLY HEAT TREATMENTS ON THE RISK OF EXPANSION ASSOCIATED WITH DELAYED ETTRINGITE FORMATION 172 COMBINED ATTACK FROM AAR AND DEF IN THE FOUNDATION BLOCKS OF A BUILDING 173 ASR AND DEF IN CONCRETE FOUNDATIONS IN THAILAND 174

20 15 th ICAAR 2016 BRAZIL THEME 01 MECHANISMS OF AAR

21 15ICAAR2016_075 USE OF SCMs ON ACR-AFFECTED CONCRETE: EXPANSION AND DAMAGE EVALUATION THROUGH THE DAMAGE RATING INDEX Pierre-Luc Fecteau 1,2*, Benoit Fournier 1 and Josée Duchesne 1 1 Department of Geology and Geological Engineering, Laval University, Québec City, Québec, CANADA 2 GHD Consultants Ltd., Lévis, Québec, CANADA Many researches have been carried out regarding Alkali-carbonate reaction (ACR) since its discovery in the 1960s in Kingston, Ontario, Canada. In many cases, more questions than answers were arising from these investigations. Also, much debate is still occurring since some researchers have suggested, in the 1990 s and recently, that ACR is a form of ASR. One of the controversial element of the above debate deals with the fact that the use of supplementary cementing materials (SCM), such as fly ash and slag, showed to be ineffective in controlling expansion in concrete incorporating alkali-carbonate reactive limestones, while similar preventive actions proved to control expansion with alkali-silica reactive aggregates such as the Spratt limestone. Control concrete specimens and specimens incorporating various proportions of SCMs (40% slag, 70% slag, 30% and 50% Class F Fly ash) were made in accordance with CSA A A test 28A Standard Practice. The expansion of the above specimens was monitored over time, while some specimens were retrieved at selected expansion levels for semi-quantitative petrographic examination. As anticipated, the expansion of the Spratt limestone is suppressed by the above proportions use of SCMs at about 2 years while the Kingston limestone at similar replacement levels of SCMs was found to be largely ineffective in controlling the expansion of concrete specimens. Higher DRI values for Kingston-bearing concretes were obtained compared to Spratt-bearing concretes at similar expansion levels. Damage observed in the DRI of the Kingstonbearing concretes is characterized by much larger occurrences of cracking in the cement paste compared to Spratt-bearing concretes. The results of the modified DRI method [10] show good to very good correlations with expansion (R 2 =0.99 Spratt and 0.89 Kingston). Abundant deposits of secondary reaction products, which are thought to correspond to calcite and brucite were identified in the ITZ between the Kingston aggregate particles and the cement paste, as well as within and impregnating the cement paste in the immediate vicinity of cracks extending from the reactive particles, with increasing occurrences through increasing expansion. This phenomenon related to dedolomitization suggests that it may play more than a secondary role in the expansion process of Kingston-bearing concretes. Keywords: Alkali-carbonate reaction, SCMs, Dolomitic limestone, Dedolomitization 20

22 15ICAAR2016_092 THE INFLUENCE OF ASR GELS COMPOSITION ON THEIR SWELLING PROPERTIES Asghar Gholizadeh Vayghan, Farshad Rajabipour, Corey Arndt The Pennsylvania State University, PA, UNITED STATES This paper investigates the effects of ASR gels chemical composition (represented as Ca/Si, Na/Si and K/Si molar ratios) on their free swelling capacity in contact with water vapor. Synthetic ASR gel minibars with twenty different chemical compositions similar to those of field ASR gels were produced and exposed to 95% relative humidity, and their free swelling strains were monitored over a period of four weeks. Response surface design concepts were implemented to design the experiments such that the non-linear effects and interactions of the test variables (i.e., Ca/Si, Na/Si and K/Si) on the swelling properties of the gels can be statistically evaluated. The results suggest that Na/Si and K/Si have linear positive effects on the free swelling of the gels, while Ca/Si shows suppressing effects when it ranges from 0.05 to 0.18, and also beyond 0.4. However, it promotes swelling as it increases in the range of 0.18 to 0.4. KEYWORDS: ASR gels, free swelling strain, minibar expansion, response surface design 21

23 15ICAAR2016_095 ALKALI AGGREGATE REACTION IN ICELAND RESULTS FROM LABORATORY TESTING COMPARED TO FIELD EXPOSURE SITE Børge Johannes Wigum 1,2, Guðbjartur Jón Einarsson 1 1 MANNVIT, Reykjavik, ICELAND 2 NORCEM HEIDELBERGCEMENTGROUP, Brevik, NORWAY In total 10 concrete mixes with the same type of a reactive- and a non-reactive aggregate, with different types of cements and amount of silica fume, were tested both by the concrete prism tests; RILEM AAR-3 and AAR-4 and by concrete cubes exposed outdoor at an exposure site for close to 8 years. In addition a concrete mix with the well-known reactive Spratt 3 aggregate was used for comparison. The main objective of this project was to provide inputs regarding some of the uncertainties still remaining regarding Alkali Aggregate Reaction and reliable performance based testing of concrete by accelerated concrete prism tests in laboratory. The effect of different types of cement, alkali level, silica fume and reactive aggregate particle sizes were investigated. For some concrete mixes, e.g. with very high- or low alkali-level, expansion results from the concrete prism tests correspond very well with expansion results from cubes at the outdoor exposure site. However, for other concrete mixes with types of cement containing inter-milled silica fume, or boosted alkali-level, it seems that these types of mixes are showing relatively high expansion in cubes at the outdoor exposure site, while most of these mixes are showing expansion below critical limits in the concrete prism tests. Contradictory results are also observed for the effect of the reactive particle size of aggregates (sand vs. gravel), where high amounts of reactive sand appears to be the governing factor for high expansion in the concrete prism tests, whereas the opposite seems to be the case for cubes at the outdoor exposure site, where the amount of reactive gravel is the governing factor. Keywords: Alkali Aggregate Reaction, Concrete Prism Testing, RILEM Test Methods, Field Exposure Site 22

24 15ICAAR2016_169 EFFECT OF ALKALI LEACHING ON EXPANSION TESTS IN LABORATORY Stéphane Multon 1, Alain Sellier 1 1 Université de Toulouse; UPS, INSA; LMDC (Laboratoire Matériaux et Durabilité des Constructions); 135, avenue de Rangueil; F Toulouse Cedex 04, FRANCE Different methods have been proposed to reassess structures damaged by Alkali-Silica Reaction (ASR). Using potential expansions test on specimens drilled from affected structures is the most usual procedure. However representing expansion of massive structures by such laboratory tests is still in question and need more investigations. Indeed, expansions on structures appear often longer and larger. Several scale effects acting on ASR expansion lead to obtain larger expansions on larger specimens according to the storage conditions of the specimens: moisture, alkali leaching and gel permeation through cracks can explain such effects. This paper presents a simplified modelling to take into account the alkali mass balance in and out of the specimens. Both the consumption of alkali by ASR-gel production and the decrease of alkali concentration in pore solution due to external leaching are considered and compared to literature data. The consequences on expansion will be evaluated through the coupling with mechanics effects. The quantification of the different scale effects on ASR expansion is important to analyze the results of expansion test performed in laboratory and the presented modeling could be useful to future diagnosis of ASR-damaged structures. Keywords: alkali, leaching, expansion, modelling, scale effect 23

25 15ICAAR2016_174 MICROSTRUCTURAL AND CHEMICAL STUDY ON AN EXPANSIVE DOLOSTONE FROM ARGENTINA Carlos A. Milanesi 1, Francisco Locati 2, Silvina Marfil 3 1 Cementos Avellaneda S. A., Ciudad Autónoma de Buenos Aires, Buenos Aires, ARGENTINA 2 CICTERRA (CONICET UNC), Córdoba, ARGENTINA 3 Geology Department, Universidad Nacional del Sur, Comisión de Investigaciones Científicas (CIC), Buenos Aires, ARGENTINA An Argentinian fine-grained dolostone has proved to react deleteriously with alkalis following a mechanism similar to ACR. As this reaction is very controversial, the rock was reassessed for going deeper into the knowledge of its reactivity. The effect of the aggregate grain size on mortar expansion was evaluated by comparing RILEM AAR-2 s test results with those from Lu et al. test method. The inhibiting effect of a high-level replacement of low-calcium fly ash was also tested. The influence of rock porosity was studied on rock and concrete prisms, stored under conditions similar to ASTM C586 and RILEM AAR-3, respectively. Microstructural and chemical studies (mercury porosimetry, polarizing microscopy, XRD, SEM-EDS) were carried out on fresh and tested rock samples. The amount of alkali-silica gel observed was very low to explain mortar or concrete expansion. Fly ash failed to inhibit mortar expansion. The only correlation observed was between concrete expansion and degree of dedolomitization. Keywords: alkali-carbonate reaction, dedolomitization, microstructure, porosity 24

26 15ICAAR2016_183 INFLUENCE OF AGGREGATE PARTICLE SIZE ON THE ALKALI-SILICA REACTION A LITERATURE REVIEW Bård M. Pedersen 1, Børge J. Wigum 2, Jan Lindgård 3 1 Norwegian Public Roads Administration, NORWAY 2 Norcem, HeidelbergCement Group, Norwegian University of Science and Technology, NORWAY 3 SINTEF Building and Infrastructure, NORWAY The literature review has shown that the size of a given alkali reactive aggregate particle has a significant effect on the rate on the alkali reaction as well as the potential for expansion and damage in concrete structures. Some very rapid reactive aggregates have a pessimum particle size in the range 0.05/0.2 mm, while coarser aggregate particles give less expansive reaction. This may be due to the high surface area leading to a faster reaction rate. On the other hand, there are a number of reports from the literature showing that very fine alkali reactive particles may have the opposite effect than causing ASR expansion they rather lead to an inhibiting effect due to pozzolanic behaviour. Some slowly reactive aggregates may have a pessimum for aggregate particles in the range 1/2 mm, while for Norwegian slowly reactive aggregates there is evidence from field structures that the coarsest particles (> 8 mm) are the most harmful. The latter effect may be explained by fracture mechanics. The effect of the aggregate particle size on the ASR expansion appears to vary greatly depending on the mineral- and rock composition, but is also depending on the exposure conditions. Consequently, the behaviour under accelerated laboratory conditions may differ from the behaviour in a field structure. Keywords: alkali-aggregate reaction, particle size, reaction rate, lab/field- correlation 25

27 15ICAAR2016_185 INFLUENCE OF SODIUM CHLORIDE ON ASR IN HIGHWAY PAVEMENT CONCRETE Colin Giebson, Katrin Seyfarth, Horst-Michael Ludwig Bauhaus-University Weimar, F.A. Finger-Institute for Building Materials Science, GERMANY After the increase of ASR-damages on highway concrete pavements in Germany it could be proved in several studies that the application of sodium chloride (NaCl) as deicing agent can trigger and accelerate ASR in concrete. A review of existing studies revealed, however, that there is no consistently accepted explanation about how NaCl influences the ASR. In the present study, experiments were performed to elucidate the mechanism and to clarify contradictions within existing theories. The findings show that an external application of NaCl to concrete does not result in an increase of the ph in the pore solution. However, there are indications that the presence of NaCl promotes the dissolution of silica directly, i.e. beyond the influence coming from the ph. Further, the formation of chloroaluminates as FRIEDEL s salt turned out to be an accompanying but not a required reaction for an ASR in concrete exposed to externally applied NaCl. Keywords: highway pavement concrete, sodium chloride, external alkalis, mechanism 26

28 15ICAAR2016_187 GLOBALISING AAR: 26 YEARS OF RILEM ENDEAVOUR Philip Nixon ¹ & Ian Sims² ¹ Associate, Building Research Establishment, UK and Chairman & RILEM Fellow, RILEM TC 106, TC 191-ARP & TC 219-ACS. 2 Director, RSK Environment Ltd, UK and Secretary & RILEM Fellow, RILEM TC 106, TC 191-ARP & TC 219-ACS. Following research in the USA during the 1930s, alkali-aggregate reactivity (AAR) was announced to a distracted world in 1940, as a major mechanism of concrete deterioration. During the following decades, countries around the world gradually discovered their own cases and varieties of AAR. A feature of the spread of the AAR experience was that countries frequently regarded their own materials and practices as exceptional, leading to a proliferation of test methods for assessing aggregate reactivity potential and/or diagnosing affected structures. RILEM 1 has an established reputation for practical research in the field of construction materials. In the late 1980s, Prof Micheline Regourd proposed the formation of a RILEM Technical Committee (TC) to review the growing plethora of AAR tests, with a view to providing guidance on a set of procedures that would be equally applicable everywhere in the world. As a result, the authors were invited to lead TC 106, which first met in 1988 and primarily focused on international tests for assessing the ASR potential of aggregates for concrete. TC 106 would be succeeded in turn by TC 191-ARP and then by TC 219-ACS, which completed its work in 2014, when the baton passed to Prof Borge Wigum and Dr Jan Lindgard, who now lead the current TC 258 AAA. This paper summarises the achievements of the RILEM TCs from 1988 to Keywords: Concrete, Aggregates, Alkali-Aggregate Reactivity (AAR), Testing, Specification. 27

29 15ICAAR2016_188 A WORLDWIDE VIEW OF AAR: UPDATING SWAMY Ian Sims 1, Alan Poole 2, 1 Director, RSK Environment Ltd, UK and co-editor The Alkali-Aggregate Reaction in Concrete, 2nd Edition 2 Consultant, Oxford, UK (formerly Queen Mary College, London University, UK) and co-editor The Alkali-Aggregate Reaction in Concrete, 2 nd Edition Timed to coincide with the 9 th ICAAR in London in 1992, Emeritus Professor Narayan Swamy edited a book entitled The Alkali-Silica Reaction in Concrete. It was a unique contribution to the limited number of text-books devoted to ASR. As well as several chapters summarising the essential principles of the mechanism, its consequences and options for its prevention or management, there were chapters describing the experiences of ASR in various countries. Over the succeeding nearly 25 years, Swamy s book has become increasingly out of date and the regional chapters now seem rather an eclectic collection, with major areas being unrepresented, despite sometimes undertaking fundamental and/or practical research into AAR. As a result, Prof Swamy kindly invited the authors to undertake an updating of the book, which they have achieved with the generous assistance of a large number of AAR experts worldwide. In addition to bringing the general science and engineering aspects of AAR and AAR-affected structures up to date, two major changes have been implemented. Firstly, the title has been subtly changed to refer to the alkali-aggregate reaction as opposed to the alkali-silica reaction, facilitating an opportunity for the work to provide a state-of-the-art account and update of the controversy over the very existence or otherwise of alkali-carbonate reactivity (ACR) and some other variants that do not wholly conform to the classic ASR model. Secondly, it was decided that the national and regional reviews would seek a complete worldwide coverage. This paper will introduce the new edition of Swamy s valuable book and celebrate the impressive international co-operation that has enabled it to be brought together. KEYWORDS Concrete, Aggregates, Alkali-Aggregate Reactivity (AAR), Durability, Worldwide Occurance 28

30 15ICAAR2016_194 INFLUENCE OF AGGREGATE SIZE ON THE DAMAGE POTENTIAL OF ALKALI-SILICA REACTION Daniel Werner, Birgit Meng, Frank Weise BAM Bundesanstalt für Materialforschung und prüfung (Federal Institute for Materials Research and Testing) Berlin, GERMANY The susceptibility of different aggregate types used in concrete to ASR is strongly associated with their petrography. The aim of this study is to assess the influence of the aggregate size on the ASR potential, in particular applied to the sand fractions in the size range of mm. The investigation concept is based on the hypothesis that at a specific particle size reactive aggregates could change their characteristic influence in mitigating ASR instead of promoting it. For the study of the size dependent behaviour mortars are prepared, considering aggregates of different reactivity, including very reactive, slow-late and quasi non-reactive types. The analysis is based on a stepwise substitution concept, in which mortars with a constant overall grain size distribution are compared, while only one size fraction of the non-reactive base aggregate is substituted by a reactive aggregate type of this specific size fraction. For the expansion experiments an accelerated mortar bar test (80 C, immersed in NaOH solution) was applied. The results show that the slow-late reactive greywacke yielded a strong reduction of the expansion below an aggregate size in the range of mm. On the other side with the very reactive borosilicate glass, the expansions increased steadily with decreasing size. To validate if the acquired expansions were caused by ASR, thin sections were analysed. Mainly, higher expansion values were consistent with extensively more amounts of ASR indicators. Keywords: alkali-silica reaction, aggregate size, mortar, expansion, microscopy 29

31 15ICAAR2016_201 ALKALI SILICA REACTION IN CONCRETE FOUNDATIONS IN THAILAND Viggo Jensen 1 *, and Suvimol Sujjavanich 2 1 Norwegian Concrete and Aggregate Laboratory LTD, Sorgenfrivein 11, 7031 Trondheim, NORWAY 2 Kasetsart University, Faculty of Engineering, Department of Civil Engineering, 50 Paholyothin Rd. Chatuchak, Bangkok 10900, THAILAND The paper demonstrates the occurrence of deleterious Alkali Silica Reaction (ASR) in mass concrete foundations from a superstructure of motorways bridges located in Thailand. ASR is caused by slow reactive sericite rock, quartzite and granite with and without cataclastic texture. Signs of reactions are similar to reaction of slowreactive aggregates reported in literature. Microstructural analyses on fluorescence impregnated polished slabs and thin sections show that ASR occurs simultaneously with delayed ettringite formation (DEF). Damage is moderate according to Norwegian experience. Thai cements are low alkali and should therefore not be susceptible to ASR for slow-reactive aggregates. In a separate paper, the authors present analyses on reaction products from the same concretes and discuss the possibility that high initial temperature and DEF might have activated slow-reactive aggregates to be alkali reactive. Keywords: Concrete, Alkali Silica Reaction (ASR), Delayed Ettringite Formation (DEF), Petrography, Scanning Electron Microscopy/Energy Dispersive X-ray spectrometry (SEM/ EDX) 30

32 5ICAAR2016_212 EFFECTS OF EXPANSION BEHAVIOR OF ASR-AFFECTED CONCRETE IN ATMOSPHERES WITH VARIOUS VALUES OF RELATIVE HUMIDITY ON SURFACE CRACKING Hiroyuki Kagimoto 1, Yukihiro Yasuda 2, Mitsunori Kawamura 3 1 Electric Power Development Co., Ltd., 1,Yanagasaki, Wakamatsu-ku, Kitakyushu, JAPAN 2 JPower design Co.,Ltd, Chigasaki, Kanagawa, JAPAN 3 Kanazawa University, Kakuma, Kanazawa, Ishikawa, JAPAN Relative humidity and strains within a massive concrete cylinder (φ450 mm 900 mm) in the drying and the re-saturating process were measured for elucidating the process of ASR surface cracking in concrete. The expansion behavior of mortars in dry atmospheres with various R.H. values and the re-saturating process was revealed. Non- or less-expansive layers were formed in near-surface regions in the concrete cylinder in the drying process, but ASR expansions actively progressed in inner portions. After re-saturating, R.H. values of near-surface regions rapidly increased with time, but expansions in the regions were found to be very small. However, in the middle portions, of which R.H. values were kept 80% ~ 90% R.H. in the drying process, expansion actively progressed, resulting in further development of surface cracks in the re-saturating process. Keywords: Alkali-Aggregate Reaction, Massive Concrete, Humidity, Expansion, Cracks Detection 31

33 5ICAAR2016_221 INVESTIGATION OF REACTIVITY OF A DOLOMITIC AGGREGATE FROM AUSTRALIA Ahmad Shayan 1*, Tetsuya Katayama 2 1 ARRB Group, 500 Burwood HWY, Vermont South, VIC 3133, AUSTRALIA 2 Taiheiyo Consulting Co. Ltd, Ohsaku, Sakura 2-4-2, JAPAN All cases of alkali-aggregate reaction (AAR) in Australia to the present time have been attributed to the alkali-silica reaction (ASR) variety of AAR, and no field cases of alkali-carbonate reaction (ACR) involving dolomitic aggregate has been recorded. Recently, doubt was raised as to the suitability of a flint-bearing dolomitic aggregate, which has largely been used in flexible road pavement construction, as concrete aggregate. As there is no service record available on the use of this aggregate in structural concrete, a detailed study was undertaken to evaluate its reactivity in concrete. This paper presents the results of various laboratory expansion tests, as well as mineralogical and microstructural examinations, and discusses the implications of the results with respect to the reactivity of the aggregate. Keywords: Dolomite, ACR, ASR, Accelerated testing, AMBT, CPT, Petrography 32

34 15ICAAR2016_222 THE INFLUENCE OF LITHIUM ON THE STRUCTURE OF ASR PRODUCTS IN CONCRETE Andreas Leemann Empa, Swiss Federal Laboratories for Material Science and Technology, Ueberlandstr. 129, 8600 Dübendorf, SWITZERLAND Apart of supplementary cementitious materials, lithium salts can be used to mitigate alkali-silica-reaction (ASR) in new structures. The mechanisms enabling lithium to be effective are not fully understood. While its impact on the structure of reaction products in model systems has been studied, no structural data on ASR products are available from lithium-containing mortar or concrete. In this study, scanning electron microscopy, optical microscopy and Raman microscopy are used to get information on the structure of lithium-containing ASR product. As optical microscopy shows, it is not refractive, indicating an amorphous material. In contrast, the ASR product without lithium is mainly refractive, proving its crystalline character. The Raman spectrograms of the lithium-containing ASR product are dominated by one band of high intensity, indicating a phase dominated by Q 3 -sites (layers of SiO 2 - tetraedra). On the other hand, the ASR product without lithium displays multiple bands, indicating a more complex structure. KEYWORDS: concrete, alkali silica reaction, lithium, reaction product, structure 33

35 15ICAAR2016_227 ALKALI SILICA REACTION MITIGATING PROPERTIES OF TERNARY BLENDED CEMENT WITH CALCINED CLAY AND LIMESTONE Aurélie R. Favier 1, Cyrille F. Dunant 1, Karen L. Scrivener 1 1 EPFL-STI-IMX LMC, Station12, CH-1015 Lausanne, SWITZERLAND A promising way to reduce CO 2 is using blend with a high level of substitution by widely available Supplementary cementitious materials (SCMs) such low grade calcined clay and limestone. Further, blended systems have well established benefits in terms of durability. ASR is the most important durability issue not related to reinforcing steel. Prevention is critical as sources of non-reactive aggregates are increasingly scarce. Since ASR occurs between alkalis in pore solution and reactive silica, most mitigation methods rely on empirical tests through SCMs. The effectiveness of SCMs in mitigating ASR is attributable mainly to the inhibition of silica dissolution when Al ions provided by the SCMs. Due to uncommon usage in the field, the mechanisms which underlie the properties of such blends are still not wholly understood. In this study, we demonstrate the performance of blends with high level of replacement (reaching 50%) of cement with limestone and calcined clay. Keywords: Alkali silica reaction, ternary blended cement, limestone, calcined clay 34

36 15ICAAR2016_231 ALKALI-AGGREGATE REACTION IN RECYCLED CONCRETE WITH AGGREGATES QUALIFIED AS REACTIVES BY THE ASTM C 1260 METHOD Jorge D. Sota *, Fabián A. Avid, Andrea S. Pereyra, Alberto J. Palacio UTN Universidad Tecnológica Nacional GIICMA Facultad Regional Concordia, Concordia, Entre Ríos ARGENTINA The durability of concrete with recycled aggregates should conform to the intended useful life of the structures. Although there have been sufficient experiences on these concretes resistant behavior, their durability has not yet been studied in the depth it requires. Many of its problems are associated with the original components of concrete demolition, the age of the demolished structure, the change in the type of structure and the new concrete cement content. In this research paper, two recycled concretes used as fine aggregate (characteristic of the constructions from Entre Ríos) are studied. The aggregates are of basaltic origin and boulder from the Uruguay River. The ASTM C 1260 method was used to show the remaining reaction potential of recycled aggregates, given some considerations that should not be neglected to ensure the durability of concretes made with this type of aggregates. Keywords: concrete, alkali-silica reaction, recycled, durability. 35

37 15ICAAR2016_243 THE ROLE OF ALKALI-DOLOMITE REACTION IN DETERIORATION OF AN AIRPORT PAVEMENT Min Deng 1,2, Benoit Fournier 3, Xiaojun Huang 2, Pierre-Luc Fecteau 3, Xianghui Lan 2, Duyou Lu 2 1 State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu , P.R. CHINA 2 College of Material Science and Engineering, Nanjing Tech University, Jiangsu , P.R. CHINA 3 Department of Geology and Geological Engineering, Laval University, Quebec, G1K 7P4, CANADA Petrographic examinations of a concrete pavement suffered cracking since 1996 showed that the dolostones used as aggregate were composed of mosaic dolomites in 10-80mm, a few of quartz and 2-5 vol% micro-crystalline quartz. Most of cracks in the pavements extended from the inner parts of dolostones to mortars, a few developed along or terminated at the boundaries of dolostones. SEM imagination showed that alkali-dolomite reaction took place in the dolostones, the coarse aggregates themselves expanded and cracked resulting in cracking of mortars due to dedolomitization. A few of micro-crystalline quartz in the coarse aggregates and in lithic fragments in fine aggregates also reacted with alkalis in pore solutions to form alkali-silica gels which expanded and cracked the concrete. The results of most of the cracks in the concrete were empty may indicate that alkali-dolomite reaction plays a major role in the deterioration of the pavements and alkali-silica reaction contributed less to cracking of the concrete. Keywords: Pavement, concrete, dolostone, alkali-dolomite reaction, alkali-silica reaction 36

38 15ICAAR2016_244 EXPANSIVE MECHANISM OF RILEM AAR-5 CONCRETE MICROBARS WITH DOLOSTONES Min Deng 1,2, Longlong Niu 3, Lingling Xu 2, Xiaodong Shen 1,2, Mingshu Tang 1,2 1 State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu , P.R. CHINA 2 College of Material Science and Engineering, Nanjing Tech University, Jiangsu , P.R. CHINA 3 College of Architecture Engineering, Nanjing Institute of Technology, Nanjing, Jiangsu 21167, P.R. CHINA Five dolostones composed of dolomites in μm and wt% micro-crystalline quartz were collected and used to prepare RILEM AAR-5 concrete microbars. The concrete microbars were then immersed into 1 mol/l NaOH solutions at 80 o C for days. The results showed that the concrete microbars expanded at a relative rapid rate during the first 28 days and then gradually slowed down. Expansion of the microbars ranged from 0.16% to 0.35% at 500 days. Reaction rims with μm width were formed. Many micro-cracks were generated and mainly caused by cracked dolostones. A few of micro-cracks developed along the boundary of the dolostones. Alkali-dolomite reaction mainly took place in the reaction rims to form fine calcite and brucite which were mixed together. Dolomite and micro-crystalline quartz outside the reaction rims were not obviously altered. There were calcite-rich zones with a width of μm in the interfacial zones next to dolostones, which formed by a reaction between CO 3 2- ions from dedolomitization of dolostones and portlandite from hydration of cements. Micro-crystalline quartz in the reaction rims with μm width was less than 0.5 wt%. Therefore, alkalisilica gels were not obviously observed in the concrete microbars. It was then concluded that alkali-dolomite reaction was responsible for expansion of the RILEM AAR-5 concrete microbars. KEYWORDS: Dolostones, Concrete microbars, Expansion, Alkali-dolomite reaction 37

39 15ICAAR2016_245 BEHAVIOURS OF REACTIVE SILICA AND DOLOMITE IN TETRAMETHYL AMMONIUM HYDROXIDE SOLUTIONS Bi Chen 1,2, Min Deng 1,2*, Xianghui Lan 2, Lingling Xu 2, Yinong Lv 1,2, Bei Huang 2 1 State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu , P.R. CHINA 2 College of Material Science and Engineering, Nanjing Tech University, Jiangsu , P.R. CHINA In this paper tetramethyl ammonium hydroxide ((CH 3 ) 4 NOH, TMAH) solutions were selected as reactants to distinguish ACR from ASR, and NaOH solutions as a comparison agent. The chemical reactions between TMAH or/and NaOH solutions and micro-crystalline quartz or/and dolomite were evaluated by chemical analysis and X-ray diffraction analysis. The expansions of rock prisms prepared with dolomitic limestones and alkali-silica reactive sandstones were tested by soaking the prisms in 80 o C TMAH and NaOH solutions. As expected, NaOH solutions may react with microcrystalline quartz in the sandstones, and caused sandstone prisms to produce significant expansion. No significant reaction between micro-crystalline quartz and 1 or 2 mol/l TMAH solutions at 80 o C takes place. Dolomite in powdered dolomitic rocks may react both with 80 o C TMAH and NaOH solutions to form calcite and brucite. It is proposed that TMAH solutions may be used to distinguish clearly alkalisilica reaction from alkali-dolomite reaction in rock prisms. KEYWORDS: Silica, Dolomite, Tetramethyl ammonium hydroxide, Rock prisms, Alkalidolomite reaction 38

40 15ICAAR2016_272 EVALUATION OF THE AVAILABLE ALKALI CONTENT IN CONCRETE THROUGH A MODIFIED HOT-WATER EXTRACTION METHOD Benoit Fournier¹, Leandro Sanchez 2, Josée Duchesne 1 and Steve Goyette 1 1 Dept. of Geology and Geological Engineering, Université Laval, Quebec, QC, CANADA 2 Department of Civil Engineering, University of Ottawa, Ottawa, ON, CANADA The available alkali content is considered a key parameter in the assessment of the residual expansion of ASR-affected concrete structures. Test methods including pore solution extraction under high pressure, as well as hotwater extraction measured on powdered concrete specimens, were proposed for assessing changes in the concrete pore solution composition over the years. This paper compares the results of two hot-water alkali extraction methods, i.e. the method originally proposed by Rogers & Hooton (1993) and revisited by Bérubé et al. (1994, 2002), and a modified version called Espresso method. The proportion of available alkalis obtained by the above two methods are compared for extractions carried out at different ages on concretes of different strengths (25 and 35 MPa) and alkali contents (ranging from 2.7 to 4.6 kg/m 3 ). The Espresso method was found to provide improved reproducibility characteristics, releasing up to 85% of the total alkali content of the concretes tested. Keywords: Available alkalis, water soluble alkalis, prognosis of ASR, residual expansion 39

41 15 th ICAAR 2016 BRAZIL THEME 02 FACTORS AFFECTING AAR

42 15ICAAR2016_011 TIME-DEPENDENT COEFFICIENT OF THERMAL EXPANSION OF AN ALKALI-SENSITIVE ROCK IN ALKALINE SOLUTION Oliver Mielich 1, Hans W. Reinhardt 2 1 Materials Testing Institute University of Stuttgart, Otto-Graf-Institute, GERMANY 2 Department of Construction Materials, University of Stuttgart, GERMANY It is well-known that temperature gradients can lead to eigenstresses the concrete. With large temperature differences between the coefficients of thermal expansion of concrete constituents cement stone and aggregate, the calculated stresses are in the range of the tensile strength of concrete. So far, it is assumed that the thermal expansions of alkali-sensitive aggregates are largely independent of the alkaline environment. This paper shows that not only the mechanical properties but also the coefficient of thermal expansion depends on the alkaline medium. What theoretical damage processes may arise during an alkali-silica reaction is, among other things, discussed in this paper. Keywords: alkali-sensitive rock, coefficient of linear thermal expansion, alkaline solution 41

43 15ICAAR2016_013 SURFACE COATING OF SILICEOUS PARTS OF AGGREGATE GRAINS BY ALUMINA CONTAINING SCM`S IN ALKALINE SOLUTIONS Klaus-Juergen Huenger 1, Mario Kositz 1, Maximilian Huenger 2, Juliane Krey 2, Mike Muehlstaedt 2 1 Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, GERMANY 2 Friedrich-Schiller-University Jena, Jena, GERMANY It is well known that SCMs containing alumina can prevent the damaging alkali silica reaction in concrete. This paper deals with the direct interactions between aggregate grain surfaces (quartzitic rock material Q1) and the dissolved amounts of SCMs (metakaolin, aluminum hydroxide). Investigations have confirmed that the presence of such SCMs can strongly decrease the silica release from aggregates in comparison to solubility experiments without SCM addition. The reason for this effect is the formation of a thin alumina containing layer (some nanometers thick) on the grain surfaces. The existence of this layer could be determined by XPS. Only this method provides data of the strongly increased alumina concentration in a thin surface area and also of the layer thickness in dependence on reaction parameters. Dissolution experiments of grains coated with such layer demonstrate the effectiveness of this process and can give a further contribution for understanding the preventing mechanisms of SCMs. Keywords: Alumina containing SCMs, inhibition, surface coating, alumina silicate layer, XPS method 42

44 15ICAAR2016_015 THE INFLUENCE OF SUPPLEMENTARY CEMENTING MATERIALS ON THE DISSOLUTION OF AGGREGATES IN ALKALINE SOLUTIONS Yvonne Scholz, Cornelia Hübert, Klaus-Jürgen Hünger Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, GERMANY Starting from expansion measurements on concrete prisms, produced with two different alkali reactive aggregates, the influence of two aluminium containing SCMs on the expansion of concrete prisms and on the solubility of the aggregates in an alkaline solution were investigated. The solubility of aggregates in an alkaline solution reflects the alkali reactivity of the corresponding aggregate. Initially, the solubility experiments with the aggregates and SCMs were made separately and then in mixtures of each aggregate and SCM. In a further step, the SCMs were stored in KOH solutions containing Ca(OH) 2. The concentrations of SiO 2 and Al 2 O 3 were determined to investigate the effect of calcium on the solving processes of SCMs. The combination of concrete expansion test and dissolution experiments of two alkali reactive aggregates and two aluminium containing SCMs allows first conclusions about the influence of such SCMs on the reactivity of aggregates. Keywords: alkali silica reaction, supplementary cementing materials (SCM), solubility of aggregate, solubility of SCM 43

45 15ICAAR2016_44 REVIEW OF METHODS TO DETERMINE THE ph AND THE FREE ALKALI CONTENT OF THE PORE SOLUTION IN CONCRETE Gilles Plusquellec 1, Mette R. Geiker 1, Josée Duchesne 2, Jan Lindgård 3, Klaartje De Weerdt 1 1 NTNU, Department of Structural Engineering, Trondheim, NORWAY 2 Université Laval, Québec, CANADA 3 SINTEF, Trondheim, NORWAY Alkali-silica reaction (ASR) in concrete is known to be induced by the dissolution reaction where the reactive silica in aggregates is dissolved by the pore solution in the concrete, followed by a precipitation reaction leading to a gel formation. The rate of the dissolution reaction depends on the ph of the pore solution, which is linked to its alkali content. It is assumed that ASR only can occur if the ph is above a critical limit called alkali threshold. The knowledge of the ph in a given concrete is of importance for durability. This paper presents a literature review of different methods to determine the ph and the free alkali content in pore solution and discusses their advantages and drawbacks. Keywords: ASR, pore solution, ph, free alkali content, concrete 44

46 15ICAAR2016_088 ASSESSMENT OF THE ALKALI-REACTIVITY POTENTIAL OF SEDIMENTARY ROCKS Isabel Fernandes 1,2, Maarten Broekmans 3, Maria dos Anjos Ribeiro 2,4, Ian Sims 5 1 University of Lisbon, Faculty of Sciences, Department of Geology, Campo Grande, Lisbon, PORTUGAL 2 ICT, Institute of Earth Sciences, FCUP, PORTUGAL 3 Geological Survey of Norway - NGU, PO Box 6315 Sluppen, N-7491, Trondheim, NORWAY 4 University of Porto, Faculty of Sciences, DGAOT, Rua do Campo Alegre, Porto, PORTUGAL 5 RSK Environment Ltd, 18 Frogmore Road, Hemel Hempstead HP3 9RT, UNITED KINGDOM The reactive forms of silica present in an aggregate depend on the origin and geological history of the rocks. The detection of specific reactive silica must be focused on characteristics such as the identification of polymorphs, the quantification of microcrystalline to cryptocrystalline quartz, and/or on the deformation manifestations for each aggregate. In this paper the types of sedimentary rocks usually exploited as aggregates for concrete, such as sandstone, greywacke, chert, siliceous limestone and mudstone, are presented. In addition, the rocks exhibiting low metamorphic grade are included when the sedimentary structure is still preserved and the features of metamorphic conditions are slight. The main characteristics of the sedimentary rocks regarding alkali-aggregate reactions are discussed and the importance of complementary methods for the detection of reactive forms of silica explained. Keywords: aggregates, reactive forms of silica, petrographic examination, sedimentary rocks 45

47 15ICAAR2016_135 STUDY ON THE FACTORS AFFECTING ALKALIS RELEASE FROM AGGREGATES INTO ASR Dora Soares 1, António Santos Silva 1, José Mirão 2, Isabel Fernandes 3, Esperanza Menéndez 4 1 LNEC, National Laboratory of Civil Engineering, Lisbon, PORTUGAL 2 Hercules Laboratory, University of Évora and Évora Geophysics Centre, Évora, PORTUGAL 3 Department of Geology, Faculty of Sciences, University of Lisbon and Institute of Earth Sciences (ICT), Lisbon, PORTUGAL 4 Institute Eduardo Torroja of Construction Science (CSIC), Madrid, SPAIN Alkaline minerals, like feldspars and micas, present in aggregates can release alkalis with time for concrete pore solution, being a contributor factor for the delaying ASR occurrence in some concrete structures (e.g. dams). Since there is presently no consensus on how to test for releasable alkalis in aggregates, a research program has been conducted to evaluate the factors that can affect the alkalis release in laboratory test conditions. This paper presents the results after 455 days evaluation of alkalis released by igneous aggregates with different grain sizes, in different alkaline solutions (Ca(OH) 2, NaOH and KOH), in two different concentrations (1M and 0.7M) -with and without addition of saturated Ca(OH) 2. The results obtained show that reducing the particle size of the aggregates leads to an increase of alkalis release to the solution, which is higher in the alkaline solutions of KOH and NaOH with saturated Ca(OH) 2. The sodium extraction is higher in 0.7M KOH, while potassium is higher in 1M NaOH. Keywords: Concrete, ASR, Alkalis release, Prevention, Mitigation 46

48 15ICAAR2016_140 ANALYSIS OF CORRELATION BETWEEN THE EXPANSION RATE AND THE INDEX OF REACTIVITY DETERMINED BY PETROGRAPHY E. Menéndez 1, R. García-Rovés 1, N. Prendes 2, S. Ruíz 3 1 Institute Eduardo Torroja of Construction Science (CSIC), Madrid, SPAIN 2 CEDEX. SPAIN 3 Dragados, S.A. SPAIN One of the most common methods to evaluate the potential reactivity of the aggregates is the accelerated mortar bar test that permits to qualify the reactivity at 14 or 28 days. The extension in the time of this test is showing the total potential expansion of the aggregates and the ratio of this expansion. With the petrographic analysis it is possible to determine the tortuosity of the interface between reactive particles or of the pores in the aggregates. These are analyzed by digital image treatment and generate an index of reactivity. This index of reactivity is a function of the quantity of reactive particles and the tortuosity of the borders of reactive grains. In this work the correlation between the expansion rate and the petrographic index of reactivity has been analyzed. The studied aggregates were used in different structures that have shown ASR after some years on environmental conditions. Keywords: Potential reactivity, expansion rate, index of reactivity, petrography, aggregates 47

49 15ICAAR2016_177 EARLY ASSESSMENT OF ALKALI-SILICA REACTION IN ALKALI-ACTIVATED FLY ASH CONCRETE SUBJECTED TO THE CONCRETE PRISM TEST (ASTM C1293) Juliana Neves 1, Stephen Salwocki 1, Farshad Rajabipour 1 1 The Pennsylvania State University, University Park, PA, USA This research investigated the susceptibility of class F alkali activated fly ash (AAFA) concrete to ASR, through ASTM C 1293 concrete prism test. At 7 months of test, the results suggested a satisfactory response of AAFA concrete in the presence of highly reactive aggregates. Conversely, OPC samples exceeded the expansion threshold at the age of 2 months. To explore the reasons for the lack of deleterious ASR expansions in AAFA concrete, SEM, pore solution analysis, and mercury porosimetry (MIP) were performed. It was found that despite using very high alkaline activators needed to trigger fly ash reaction, OH - ions in the AAFA pore solution were rapidly consumed in reaction with fly ash and became significantly less available to attack aggregates and generate ASR. Also, AAFA pore solution contained elevated levels of dissolved Al, which helps in mitigating aggregate dissolution and as such, ASR. In comparison with OPC paste, AAFA pastes had similar or larger porosity and average pore size, despite their significantly lower ASR activity. This rules out a hypothesis that ASR is mitigated in AAFA concrete because of its low mass transport kinetics (e.g., permeability). KEYWORDS: alkali-silica reaction, alkali-activated fly ash, pore solution analysis 48

50 15ICAAR2016_190 FIELD AND LABORATORY EXAMINATIONS OF AN ASR-AFFECTED BRIDGE VARIATION IN CRACK EXTENT AND WATER CONTENT Eva Rodum, Bård M. Pedersen, Ragnhild Holen Relling Norwegian Public Roads Administration, Trondheim/Bergen/Ålesund, NORWAY The Elgeseter bridge was built in Trondheim during the period ASR damages were documented in the early 1990s and frequent examinations regarding rate of expansion and relative humidity, have been performed since The effect of both hydrophobic impregnation and Carbon Fiber Reinforced Polymer (CFRP) strengthening have been tested. Due to renovation works during the summer , the bridge was included as an object in an on-going R&D project. Crack widths were measured on selected columns and a large number of cores were drilled both from the columns and the bridge deck. The cores were subject to determination of the water content and internal cracking in the concrete. The results from both previous ( ) and the latest ( ) examinations of moisture content and cracking on Elgeseter bridge are summarized in this paper. Keywords: Alkali-silica reaction (ASR), concrete, bridge deck, bridge columns, crack extent, water content 49

51 15ICAAR2016_191 INFLUENCE OF SIMULTANEOUS CYCLIC LOADING AND EXTERNAL ALKALI SUPPLY ON THE ALKALI-SILICA REACTION IN CONCRETE PAVEMENTS Frank Weise, Katja Voland, Stephan Pirskawetz, Birgit Meng BAM Federal Institute for Materials Research and Testing, Berlin, GERMANY In recent years the German motorway network has seen an increase in the occurrence of damage to concrete road surfaces which can be attributed to the alkali-silica reaction (ASR). In view of the often drastically reduced life expectancy of road surfaces due to ASR, research activity in this field has notably increased. Alongside preventative measures in concrete technology, the main research focus up to now has been the development of performance-oriented testing procedures for ASR prevention. This included more specifically the accelerated simulation of climatic effects and external alkali penetration on road surfaces. The effects of mechanical pre-damage resulting from cyclic traffic loading and climatic impact had previously not been taken into consideration. Since 2011, the five-partner research group 1498 sponsored by the German Research Foundation (DFG) has been pursuing research on how simultaneous cyclic loading and external alkali penetration impacts destructive ASR in road surface concretes. The depiction of the myriad degradation and transport processes necessary for an understanding of these effects requires close interaction between experiments and their multi-scale modelling. This paper aims to focus on the aforementioned experiments by means of innovative testing techniques. The research is founded on a series of cyclic fatigue tests performed on large-format beams, both with and without previous application of a sodium chloride (NaCl) solution, with simultaneous tracking of crack development. Subsequently, smaller test specimens were extracted from the pre-damaged beams for further experiments. These included the spatial visualization and quantification of fatigueinduced cracks using micro X-ray 3D-computed tomography (3D-CT). Additionally, the effects of fatigue-induced cracks on alkali transport were investigated using Laser- Induced Breakdown Spectroscopy (LIBS). Subsequent storage of the small-format test specimens, with and without cyclic pre-damage, in an ASR-conducive environment then provided initial findings on the influence of fatigue-induced predamage on the ASR. Keywords: alkali-silica reaction, ASR, pavement concretes, mechanical pre-damage, external alkali supply 50

52 15ICAAR2016_207 ASR - PERFORMANCE TESTING: MAIN FINDINGS IN THE NORWEGIAN COIN PROJECT Jan Lindgård 1, Terje F Rønning 2, Michael D.A. Thomas 3, Benoit Fournier 4, António Santos Silva 5 1 SINTEF Building and Infrastructure, Trondheim, NORWAY 2 Norcem Heidelberg Cement, Brevik, NORWAY 3 University of New Brunswick, Fredericton, CANADA 4 Université Laval, Quebec, CANADA 5 National Laboratory for Civil Engineering (LNEC), Lisbon, PORTUGAL Work is going on in several countries to try to develop a reliable performance testing concept for ASR. This topic was also focused on in the Norwegian R&D project "COIN" ( ). The work was closely linked to the work within RILEM TC 219- ACS ( ). This paper gives a summary of the main findings in the COIN program. The main aim of part I (PhD study) was to document the effect of various curing and storage conditions on the concrete internal moisture state, the extent of alkali leaching and ASR related expansion. The study documented that the main parameter controlling the ASR expansion measured in the laboratory is extent of alkali leaching. Based on the findings in part I, a comprehensive follow-up study (part II) has been performed. 20 different concrete mixtures, including six aggregate types and four cement types, have been performance tested according to the most promising test procedures in part I. Moreover, two field exposure sites have been established in order to document the laboratory/field correlation, one in Norway (at SINTEF) and one in Portugal (at LNEC). Keywords: Alkali-Silica Reaction (ASR), performance testing, alkali leaching, moisture state, field exposure sites 51

53 15 th ICAAR 2016 BRAZIL THEME 03 TESTING FOR POTENTIAL AAR

54 15ICAAR2016_014 MODIFICATIONS OF THE CONCRETE PRISM TEST WHEN TESTING LOW-ALKALI CEMENT WITH SCM SYSTEMS FOR MITIGATION OF ALKALI-SILICA REACTION Soley U. Einarsdottir 1, R. Douglas Hooton 1 1 University of Toronto, Toronto, ON, CANADA When carrying out laboratory tests for ASR, the currently used ASTM C1260 and C1293 methods cannot be used for evaluating the benefits of using low-alkali cement, with or without supplementary cementitious materials (SCM). This has been found by the concrete industry to be a severe limitation on assessment of ASR mitigation options in some regions of North America (especially in the western parts of Canada and the US, where most cements are low-alkali). The effect of cement alkali content and SCM replacement on the expansion and leaching in the concrete prism test was investigated, as well as ways to minimize alkali leaching during the test. Approximately 45% of the alkalis were leaching from 100% PC concrete prisms during the two year test period, regardless of cement (high-, medium- or low-alkali cements). Use of SCM replacements decreased the alkali leaching to around 25%, likely due to a more impermeable pore structure. The most effective way to minimize the leaching was to cover each prism with a plastic bag, where the magnitude of alkali leaching was reduced to only 10%. Also, by modifying the procedure for boosting the level of alkalis in the C1293 concrete prism test and with the use of improved storage conditions to minimize alkali leaching from the samples, it is possible to use this test for evaluating the benefits of concrete mixtures made with low-alkali cements and combinations with SCMs. Keywords: Alkali-Silica Reaction, low-alkali cement, test methods, preventive measures, guidelines 53

55 15ICAAR2016_055 TRACKING ALKALI MIGRATION AND LEACHING IN THE AUTOCLAVED CONCRETE PRISM TEST Stephanie G. Wood 1, Ashley V. Sutton 1, Eric R. Giannini 1 1 The University of Alabama, Tuscaloosa, AL, USA The progression of alkali-silica reaction consumes alkalis to form reaction product, leading to a reduction in hydroxide and alkali concentrations in the pore solution over time. However, for specimens in the ASTM C1293 concrete prism test (CPT), the reduction in pore solution alkalinity is strongly influenced by alkali leaching. An autoclaved concrete prism test has shown promise in correctly classifying aggregates that the CPT fails to identify as reactive. Specimens are identical to those of the CPT with the exception that the equivalent alkali content is boosted to 3.0% by mass of cement. Prisms are autoclaved at a temperature of 133 C for 24 hours, providing final results in just four days. The amount of alkali leaching is determined by analyzing samples of autoclave water and expressed pore solution using ICP-OES. Results show alkali leaching of only 4-11%, which is significantly lower than the 12-25% alkali leaching in the CPT. Keywords: alkali-silica reaction, alkalis, pore solution, autoclave, alkali leaching 54

56 15ICAAR2016_056 INTER-LABORATORY COMPARISON OF EXPANSIONS FROM THE AUTOCLAVED CONCRETE PRISM TEST Stephanie G. Wood 1, Margaret L. Kimble 2, Nathan D. Klenke 1, Bryce Fiore 3, Jennifer E. Tanner 3, Eric R. Giannini 1 1 The University of Alabama, Tuscaloosa, AL, USA 2 GEI Consultants, Inc., Denver, CO, USA 3 University of Wyoming, Laramie, WY, USA A widely-accepted test method for determining the alkali-silica reactivity of aggregates is the ASTM C1293 concrete prism test (CPT). Of all the standardized test methods designed for this purpose, the CPT shows the best correlation with field behavior. However, the one-year test duration renders the CPT unappealing. The autoclaved concrete prism test (ACPT), was developed to reduce this testing time. The ACPT uses concrete prisms like those in the CPT but with higher alkali loading. Prisms are conditioned in an autoclave for 24 hours at 133 C. Early results show a good correlation to known aggregate field performance. To determine repeatability of the ACPT, The University of Alabama (UA) and the University of Wyoming independently tested four aggregates from Wyoming paired with a known non-reactive counterpart. Results indicate a better inter-laboratory correlation with coarse aggregates than with fine aggregates, with UA consistently obtaining higher expansions for fine aggregates tested. Keywords: alkali-silica reaction, autoclave, expansion, interlaboratory study, test repeatability 55

57 15ICAAR2016_058 POST-MORTEM REVIEW OF CONCRETE PRISM TEST SPECIMENS: PETROGRAPHIC OBSERVATIONS Fred Shrimer and Benjamin Hudson Golder Associates, Vancouver, CANADA Upon completion of numerous Concrete Prism Tests (CPT) that were conducted over a period of more than twelve years, prism specimens were selected for further evaluation. This was done to provide/develop further insight regarding the effects of the test on the concrete samples, the responses of various aggregate lithologies within the test regime, and to generate observations that could be helpful in future CPT programs. The primary tool used in these analyses was Petrographic Examination, supplemented in some cases by the Damage Rating Index (DRI) procedure. Comments and discussion provide insights that have been accumulated over several years of conducting CPT programs. These include expansions that were either greater than or less than those experienced in previous testing programs of the same sources; a mismatch of expansion data with petrographic data, where AAR testing show either an expansion or none, where petrographic examination indicated that the opposite would be expected; and significant damage in prism or bar samples that impaired running the test. Keywords: Alkali-Aggregate Reaction; Concrete Prism; Petrographic Examination; Damage Rating Index 56

58 15ICAAR2016_065 IMPROVING THE RELIABILITY OF THE ASTM C1260 ACCELERATAED MORTAR BAR TEST R. Douglas Hooton 1, and Farideh Golmakani 1 1 University of Toronto, Dept of Civil Engineering Toronto, ON, CANADA Due to its rapidity, the ASTM C1260 accelerated mortar bar test (AMBT) is the most commonly used technique for examining the potential alkali-silica reactivity (ASR) of concrete aggregates. Unfortunately, with some many types of aggregates, results obtained with this test are often unreliable and lead to identification of reactive aggregate as non-reactive and vice versa. One concern is that ettringite decomposes at 80 C, leading to increased sulfate in solution, resulting in reduced hydroxyl concentration. To improve the reliability of this test, modifications to the current procedure were evaluated, namely, reduction of the storage temperature from 80 C to 60 C and 40 C. Standard and modified versions of the AMBT were performed using a suite of correctly and incorrectly identified aggregates. Pore solutions of sealed cement paste exposed to 40 C, 60 C, and 80 C for 35d were also extracted and analyzed. Results show that lowering the storage temperature to 60 C increased the hydroxyl concentration of pore solutions and in some cases, 14d expansions increased dramatically. As well, extending the 60 C test period to 28d was effective in terms of more reliably identifying the reactivity of some aggregates. The effects of mitigation using pozzolans and slag on both the pore solution composition and expansion are being investigated. Keywords: Accelerated mortar bar test; ASTM C1260; Pore solution alkalinity; Temperature effects 57

59 15ICAAR2016_068 DEVELOPING A RAPID CONCRETE TEST TO ASSESS ALKALI-SILICA REACTION Anol K. Mukhopadhyay 1, Kai-Wei Liu 1 1 Texas A&M Transportation Institute, Texas A&M University, TX, USA The concrete prism test (ASTM C 1293) has been considered as a reliable alkali silica reaction (ASR) test method, but long test duration and alkali leaching are the inherent limitations of this method. A rapid concrete cylinder test (RCCT) has been developed to access alkali silica reactivity of aggregates in concrete. In RCCT method, a cylindrical concrete specimen 7.62 x cm (3 x 6 inches) is immersed in a soak solution of equal chemistry with pore solution (leach-proof condition) and the length change is measured through LVDT and data acquisition system at 60 C. Cylinders made with highly reactive borosilicate glass balls were tested first to validate the proposed method. The automatic data collection system under constant temperature and leach-proof condition ensure reliability of the RCCT method. RCCT method can be operated at different alkali loadings. The data shows that RCCT method with relatively low alkali loadings (i.e., 2.7 kg/m 3 (4.5 lb/yard 3 ) as opposed to 5.3 kg/m 3 (8.9 lb/yard 3 ) in the current ASTM C 1293 method) can effectively be used to assess aggregate reactivity in a relatively short time (i.e., days). A favorable comparison between the proposed RCCT and ASTM C 1293 has been observed. RCCT method has shown promises to optimize fly ash contents in order to develop safe ASR-resistant mixes. The RCCT method also has the ability to test job mix. Keywords: alkali-silica reaction, new rapid test, concrete cylinder test, testing at varying alkali loadings 58

60 15ICAAR2016_073 RILEM TECHNICAL COMMITTEES (TCs) PAST AND PRESENT. TC 258-AAA: AVOIDING ALKALI AGGREGATE REACTION (AAR) IN CONCRETE PERFORMANCE BASED CONCEPT ( ) Børge Johannes Wigum 1,2, Jan Lindgård 3 1 NORCEM HEIDELBERGCEMENT GROUP NORTHERN EUROPE, Brevik, NORWAY 2 NTNU, Norwegian University of Science and Technology, Trondheim, NORWAY 3 SINTEF Building and Infrastructure, Trondheim, NORWAY Since 1988, RILEM Technical Committees (TCs) have been seeking to establish universally applicable test methods for assessing the alkali-reactivity potential of aggregates, and later for concrete mixes. The TC 106 ( ) focused on accelerated aggregate tests, and presented the findings at the International Conferences on Alkali Aggregate Reaction (ICAAR) in Kyoto (1989), London (1992), Melbourne (1996) and Quebec (2000). The successor committee TC 191-ARP ( ) also included work on Diagnosis/Appraisal & Specification, and presented the findings at the ICAAR in Beijing (2004). The TC 219-ACS ( ) introduced work on Performance testing & Modelling, and presented findings at the ICAARs in Trondheim (2008) and in Austin (2012). The major recommendations from the last TC were published as a RILEM State-of-the-Art Report in The 4 th RILEM TC on AAR, the TC 258-AAA was established 2014, scheduling to finish the work on performance-based assessment in The work in this TC is concentrated in the three Work Packages (WPs) dealing with: Accelerated performance testing in laboratory (WP1), laboratory testing vs. field exposure sites (WP2), and assessment of alkali inventory in concrete (WP3). Keywords: Alkali Aggregate Reaction, RILEM, Regulations, Performance testing 59

61 15ICAAR2016_081 ALKALI SILICA REACTION IN AGGREGATES DERIVED FROM THE VALORISATION OF WASTES FROM THE AGATE MINING Natália dos Santos Petry 1, Ângela Borges Masuero 2, Ana Paula Kirchheim 3 1 UFRGS Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, BRAZIL 2 UFRGS Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, BRAZIL 3 UFRGS Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, BRAZIL The state of Rio Grande do Sul is the third producer of precious stones in Brazil, which also elucidates a significant volume of wastes generated along the production of agate products. It is well known that agate is constituted mainly by quartz, which might shows susceptibility for alkali-silica reaction, if these materials are used as aggregates in concrete/mortar mixtures. Thus the objective of this study is to assess the potential development of alkali-silica reaction in mortars based on different blends agate waste. For this purpose, accelerated tests with mortar bars were performed according to NBR standard. The reactivity was evaluated using the standard cement indicated by NBR and with white Portland cement. The studies indicate that agate waste with a particle size distribution between 150 um a 4.8 mm is highly reactive. However, the inclusion of powdered agate waste reduces the deleterious effect of alkali-silica reaction and expansions higher than 0.19% were not identified. Keywords: agate; mining waste; alkali-aggregate reaction; 60

62 15ICAAR2016_084 IMPORTANCE OF ALKALI-WRAPPING IN CONCRETE PRISM TESTS Kazuo Yamada 1, Yasutaka Sagawa 2, Takahiro Nagase 3, Shoichi Ogawa 4, Yuichiro Kawabata 5,6, Akihiro Tanaka 2 1 National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Tsukuba, JAPAN 2 Kyushu University, Department of Civil and Structural Engineering, Fukuoka, JAPAN 3 Taiheiyo Consultant, Analytical Technology Division, Sakura, JAPAN 4 Taiheiyo Consultant, Sales & Marketing Division, Tokyo, JAPAN 5 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la-Vallée Cedex 2, FRANCE 6 Port and Airport Research Institute, Structural Engineering Division, Yokosuka, JAPAN Concrete prism tests (CPT) for alkali aggregate reaction (ASR) are considered as a relatively reliable method covering the limitations of various aggregate tests. However, CPT has two problems alkali leaching and drying. As an aggregate test, the CPT is a valuable because the alkali threshold for expansion can be determined by comparison with existing damages. However, as a performance test, these unintended effects need to be prevented and, wrapping concrete prisms with wet cloth containing an alkaline solution with the same ph as that of pore solution of concrete named as alkali wrapping (AW)-CPT is proposed in this study. This avoids the movement of alkalis between the cloth and the prisms and makes the acceleration conditions are clear and stable. The analysis of the cloth used for AW- CPT at various acceleration conditions indicates the presence of significant amount of silica leaching depending on the conditions and the mechanisms discussed. Keywords: concrete prism test, alkali wrapping, performance test, alkali leaching, drying 61

63 5ICAAR2016_097 RE-EVALUATION OF TESTING PARAMETERS IN THE ACCELERATED MORTAR BAR TEST Tyler Deboodt 1, Andrew Wilson 1, Jason H. Ideker 1, Matthew P. Adams 2 1 Oregon State University, Corvallis, OR, USA 2 New Jersey Institute of Technology, Newark, NJ, USA The accelerated mortar bar test (AMBT) is used as a rapid screening method to determine the potential of an aggregate to be alkali-silica reactive. However, aggregate grading, temperature, and the concentration of the NaOH soak solution will affect the observed reactivity of aggregates. This research presents a study of aggregate reactivity using the AMBT in which an examination of the impact of temperature, normality, and aggregate grading on expansion was determined. A siliceous, fine aggregate was tested to assess the impact of each of these parameters in the AMBT (according to ASTM C1260), and ultimately compared to concrete prism tests (CPT-ASTM C1293). Under standard testing procedures this aggregate was determined to be very highly reactive, according to ASTM C1778, with an expansion of 0.49% at 14 days, yet was deemed non-reactive in the CPT with an expansion of 0.02% at 1 year. To assess the effect of temperature and aggregate preparation, a standard 1 N NaOH solution was used. The temperature study was done at 23 C, 38 C, 60 C, and 80 C. As received and the prescribed grading were used to assess the effect of aggregate preparation. A study of the impact of normality examined NaOH solutions of 0.5 N, 0.75 N, 1 N, 1.25 N, 1.5 N, and 1.75 N at 80 C. It was found that expansion peaked in a 0.75 N NaOH solution at 14 days. Expansion was shown to increase as temperature increased, particularly above 38 C. It was shown that modifications to the AMBT test typically did not correspond to the results in the CPT. Keywords: temperature, normality, AMBT, ASR, alkali content 62

64 5ICAAR2016_114 CAN METAKAOLIN-BASED GEOPOLYMERS SUFFER FROM ALKALI SILICA REACTION? Raphaëlle Pouhet 1, Martin Cyr 1, Stéphane Multon 1 1 Université de Toulouse, UPS, INSA, Laboratoire Matériaux et Durabilité des Constructions, Toulouse, FRANCE This research assesses the behaviour of metakaolin-based geopolymers in the presence of alkali-reactive aggregates. Geopolymer mortars were made with flash metakaolin and sodium waterglass solution in presence of seven different aggregates, each having different levels of reactivity to alkali-silica reaction (ASR). The behaviour of geopolymer in presence of such reactive aggregates was investigated by monitoring the dimension changes in accelerated conditions at 60 C and 95% RH for up to 250 days. SEM and EDX analyses were also performed at 170 days to visualize the newly formed products. A comparison with an ordinary Portland cement (OPC) was made for all aggregates in order to evaluate how strongly geopolymers were affected by ASR. Results showed that geopolymers, although they contained high concentrations of alkalis, were more able to resist ASR than OPC was, and no characteristic swelling was observed for the geopolymer specimens. The conclusions were the same with other test conditions, e.g. by varying the temperature of the test or the size of the specimens. Only aggressive conditions, like immersion in a 1M NaOH solution, led to a non-negligible expansion of geopolymer mortars, but with very slow reaction kinetics compared to OPC. The non-accelerated test confirmed that the geopolymer seemed to develop no harmful reaction in presence of reactive aggregates and optimal conditions for ASR. The non-swelling behaviour of metakaolin-geopolymers could be due to various phenomena: fast decrease in the ph, lack of calcium in the new-formed products, or accommodation of the gels in the porous network. The results of this paper allowed us to conclude that, under the same condition and in spite of their very high concentration of sodium, geopolymers have a higher durability than OPC regarding the alkali-silica reaction. Keywords: Geopolymer, Alkali silica reaction, Metakaolin, Mortar, Durability. 63

65 15ICAAR2016_125 THE USE OF ACCELERATED MORTAR BAR EXPANSION RATES AND REACTION KINETIC MODEL IN DETECTING ALKALI-SILICA REACTIVE AGGREGATES Vute Sirivivatnanon 1, Warren South 2 and William A (Tony) Thomas 3 1 University of Technology Sydney, Sydney, AUSTRALIA 2 Cement Concrete and Aggregates Australia, AUSTRALIA 3 Boral Limited, AUSTRALIA Two new Australian Standard test methods to detect alkali-silica reactivity (ASR) of aggregates: AS Accelerated Mortar Bar Test (AMBT) and AS Concrete Prism Test (CPT); were published in September Both test procedures were adopted correspondently from the ASTM C1260 and ASTM C1293 test methods but with different performance limits. The use of short-term AMBT expansion rates between 10 to 21 days have been found effective in classifying nonreactive, slowly reactive and reactive aggregate in better agreement to the performance of most of the reported outdoor-exposed large concrete blocks or field structures. The results support the use of AMBT to screen non-reactive aggregates and the CPT to confirm reactive aggregates. In addition, the application of reaction kinetics model on the AMBT expansion results further improves the accuracy of predicting potential ASR consistent with the CPT thus putting more credence to this short-term accelerated test method. Keywords: Accelerated mortar bar test, alkali-silica reactivity, reaction kinetics, expansion rate, slowly reactive aggregate 64

66 15ICAAR2016_130 AN ACCELERATED AND MORE ACCURATE TEST METHOD TO ASTM C1293: THE CONCRETE CYLINDER TEST Stephen Stacey 1, Kevin Folliard 1, Thano Drimalas 1, Michael D.A. Thomas 2 1 University of Texas at Austin, Austin, TX, UNITED STATES 2 University of New Brunswick, Fredericton, New Brunswick, CANADA In recent years there has been a growing understanding that ASR test methods such as the accelerated mortar bar test (ASTM C1260/AMBT) and the concrete prism test (ASTM C1293/CPT) are producing unreliable results as compared with the long term exposure block data, and so a new more rapid and reliable test has been developed known as the concrete cylinder test (CCT). The keys to the CCT test method is preventing the leaching out of alkalis over the lifetime of the test, utilizing existing measurement practices and making onsite procurement and testing possible. Through the use of concrete cylinder molds we can create a closed system that insulates the specimen preventing leaching, while simultaneously promoting more direct linear expansion. The cylinders are pinned at the top and bottom surface, and cast 6 mm short from the top of the mold to leave room for water to pond and provide a source of moisture to the concrete cylinder. Results have shown that the CCT can produce final expansion values in a mere 15 weeks compared to the same mixture at 1 year for CPT. CCT removes the error associated with leaching, and allows for expansion seen in exposure blocks at the University of Texas at alkali levels lower than 1.8 kg/m 3, where mixture does not expand in standard CPT. CCT permits testing at these lower alkali thresholds to see if they would expand in the test providing the ability to evaluate actual job mixtures, something that has never been possible with the AMBT, CPT, or any other ASR test method. Keywords: Alkali Silica Reaction, Accelerated Concrete Cylinder Test, Low Alkali Testing, Mix Design Confirmation, Field Applicable 65

67 15ICAAR2016_133 PORTUGUESE EXPERIENCE IN ASR AGGREGATE ASSESSMENT António Santos Silva 1, Isabel Fernandes 2,3, Dora Soares 1, João Custódio 1, A. Bettencourt Ribeiro 1, Violeta Ramos 3, Sara Medeiros 4 1 LNEC, National Laboratory for Civil Engineering, Lisbon, PORTUGAL 2 Department of Geology, Faculty of Sciences, University of Lisbon, Lisbon, PORTUGAL 3 Institute of Earth Sciences (ICT), PORTUGAL 4 Department of Geosciences, University of Azores, Ponta Delgada, PORTUGAL Although considerable efforts have been made worldwide regarding alkalisilica reaction (ASR) prevention and mitigation, including the approval of new national and international regulations, several concrete structures are still being diagnosed with ASR. In Portugal, the new cases of ASR pertain to concrete produced mainly with igneous aggregates, whose potential reactivity is difficult to assess, notably on granitic and basaltic rocks. The most effective way to prevent ASR is an adequate knowledge of the alkali reactivity of the aggregate, which requires the application of appropriate tests and criteria to enable a correct classification. In the last 4 years a research program conducted in Portugal has evaluated more than 90 aggregates of different mineralogy and/or texture. The test campaign included petrography, ASTM C1260, RILEM AAR-3 and RILEM AAR-4.1 test methods. In this paper the results of ASR reactivity evaluation obtained in a group of granitic and basaltic aggregates are presented and discussed. From the results obtained, proposals to improve the reliability of existing test-methods are presented. Keywords: ASR, aggregates, reactivity, test-methods, granites 66

68 15ICAAR2016_134 ASR IMPACT ON CONCRETE WITH RECYCLED AGGREGATES Miguel Barreto Santos 1, António Santos Silva 2, Jorge de Brito 3 1 CERIS/ICIST, Instituto Politécnico de Leiria, Escola Superior de Tecnologia e Gestão, Leiria, PORTUGAL 2 LNEC, Laboratório Nacional de Engenharia Civil, Lisboa, PORTUGAL 3 CERIS/ICIST, Universidade de Lisboa, Instituto Superior Técnico, Lisboa, PORTUGAL Nowadays, with the increase of sustainable construction criteria, the incorporation of recycled coarse aggregate concrete (RCA) in concrete has become a reality. Alkali-silica reaction (ASR) is one of the most concerning degradation causes of concrete with natural aggregates. The incorporation of RCA in concrete raises the ASR issue. The main goal of this article is to present the first results of a research program on ASR in concretes with RCA, using different replacement levels of natural coarse aggregates (NCA) with RCA. For this purpose, controlled RCA were used, which were artificially aged to simulate an old and a recent concrete. The influence of the concrete source, as well as the cement type on ASR development in concrete with RCA was evaluated. The study is still ongoing, but the results obtained so far indicate that the incorporation of 20% reactive RCA did not show a marked expansion, i.e. their partial incorporation seems feasible. The highest expansions were obtained with a 100% reactive RCA and also with a higher strength class cement. Keywords: recycled aggregates, ASR, durability, concrete, degradation 67

69 15ICAAR2016_136 TO BE OR NOT TO BE... ALKALI-REACTIVE. A CHALLENGE FOR THE PETROGRAPHIC METHOD Isabel Fernandes 1,2, Maria dos Anjos Ribeiro 2,3, Helena CB Martins 2,3, Fernando Noronha 2,3, Dora Soares 4, António Santos Silva 4, Maarten ATM Broekmans 5, Ian Sims 6 1 University of Lisbon, Faculty of Sciences, Department of Geology, Campo Grande, Lisbon, PORTUGAL 2 ICT, Institute of Earth Sciences, FCUP, PORTUGAL 3 University of Porto, Faculty of Sciences, DGAOT, Rua do Campo Alegre, Porto, PORTUGAL 4 LNEC, National Laboratory for Civil Engineering, Av. do Brasil 101, Lisbon, PORTUGAL 5 Geological Survey of Norway - NGU, PO Box 6315 Sluppen, N-7491, Trondheim, NORWAY 6 RSK Environment Ltd, 18 Frogmore Road, Hemel Hempstead HP3 9RT, UNITED KINGDOM The mechanisms involved in alkali-aggregate reaction and the characteristics of reactivity of some aggregates are not completely understood, although tens of thousands of mortar and concrete prisms have been tested in the laboratory and field exposure sites have been installed in a number of countries. Aggregates are the least well understood component in the alkali-aggregate reactions and, surely, the most difficult to assess. This happens not just because the materials used as aggregates are widely variable in origin, geological history, composition, texture and degree of alteration, but also because rocks that behave as innocuous in certain areas of the world appear to perform as reactive elsewhere. In consequence, the petrographic assessment of the aggregates is commonly not enough to classify an aggregate as innocuous or potentially reactive. In this paper questions are raised concerning slow reactive rock types, including suggestions about the possible forms of silica present and their identification. Keywords: slow reactive aggregates, strained quartz, petrography, complementary methods 68

70 15ICAAR2016_138 ALKALI RELEASE OF AGGREGATES. EFFECTIVENESS OF DIFFERENT SOLUTIONS AND CONDITIONS OF TEST E. Menéndez 1, R. García-Rovés 1, B. Aldea 1, S. Ruíz 2 1 Institute Eduardo Torroja of Construction Science (CSIC), Madrid, SPAIN 2 Dragados, S.A. SPAIN The alkali release of aggregates can constitute a source of alkalis in concrete exposed to wet environment for long time. Feldspars are one of the minerals that can release alkalis to the concrete with the time. With granite aggregates has been observed the formation of reaction products in the interface with the paste due to the alkali release from sodium and potassium feldspars. This is observed after more than 25 years of the exposition. It is necessary to evaluate the potential amount of alkalis releasable to define the formulation of concrete before the manufacturing of it. To evaluate the alkali release of aggregates different solutions and test conditions are used. In the present work the potential alkali release of a granodiorite rock has been determined using different solutions and test conditions. The influence of the type of ions presents in the solution, the concentration of them and temperature have analyzed. Keywords: Alkali release, aggregates, extraction, test method, effectiveness 69

71 15ICAAR2016_156 MANAGING ALKALI-AGGREGATE REACTIVITY: NORTH AMERICAN APPROACH Jason H. Ideker 1, Thano Drimalas 2, Benoit Fournier 3, Kevin J. Folliard 2, Doug Hooton 4, Michael D.A. Thomas 5 1 Oregon State University, Corvallis, Oregon, USA 2 The University of Texas at Austin, USA 3 Universite Laval, Quebec City, Quebec, CANADA 4 University of Toronto, Toronto, Ontario, CANADA 5 University of New Brunswick, Fredericton, New Brunswick, CANADA Over the past 25 years North America has developed a uniform and aggressive approach to managing the risk of alkali-aggregate reactivity in concrete. Currently, the Canadian Standards Associate CSA (Canada), Federal Highway Administration FHWA (USA), American Association of State Highway and Transportation Officials - AASHTO (USA) and ASTM International (USA) all now follow a nearly identical approach to the identification of reactive aggregates and the mitigation of potential reaction. The approach relies heavily on the use of the accelerated mortar bar test and the concrete prism test for assessing aggregate reactivity. Field history and petrography are also incorporated as options in identification of reactive aggregates. If an aggregate is found to be potentially alkali-carbonate reactive it is recommended to avoid using that aggregate in concrete construction. If an aggregate is found to be potentially alkali-silica reactive users can follow either a performance-based or a prescriptive-based approach for avoiding the reaction. This paper will cover an overview of the approach, highlight potential challenges for implementing the method and make recommendations for future modifications to improve the identification and mitigation of potential reactive aggregates for successful use in field concrete. Keywords: alkali-aggregate reactivity, risk, risk management, performance-based, prescriptive approach 70

72 15ICAAR2016_162 POTENTIAL OF NON-DESTRUCTIVE AND MICRO ANALYTICAL TECHNIQUES APPLIED TO THE STUDY OF DAMAGE ASSESSMENT AND MITIGATION IN ASR PRONE STRUCTURES Aluisio Caldas e Silva 1,2,3, Sandro Marden Torres 2, Andressa de Araújo P. Vieira 2, Alberto Jorge C. T. Cavalcanti 1 ; Patrícia Neves Silva 1, Tiberio W. C. O. Andrade 2 1 CHESF Divisão de Engenharia Civil da Geração, Recife, PE, BRAZIL 2 UFPB Departamento de Engenharia de Materiais, João Pessoa, PB, BRAZIL 3 University of Portsmouth - School of Civil Engineering and Surveying, Portsmouth, UNITED KINGDOM Understanding Alkali Aggregate Reaction (AAR) is of great importance for the serviceability of concrete structures. The total ruin of AAR affected structures is rarely reported, which might give an indication that other pathologies are often to blame. The scarceness or perhaps inexistence of related examples of total failure might give an impression that AAR is of less concern for engineers than other most common pathologies. In a long-term perspective, extensive cracking in damaged concretes leads to the potential of facilitating other degrading mechanisms governed by diffusion as well as to induce steel corrosion. The overall effect of AAR has still an important role as far as design, construction and maintenance are concerned, especially in the case of large structure. The Companhia Hidrelétrica de São Francisco (CHESF) is the biggest electric company of Brazil. Since half of its 15 hydroelectric dams presented some sort of AAR in different levels, CHESF designed a comprehensive research, development and innovation (R&D+I) programme in order to: (i) enhance the quality of monitoring the progress of damage; (ii) improve and develop effective methods for detection (iii) evaluate the potential of innovative mitigation strategies. In this sense, this paper summarizes some preliminary results obtained by several non-destructive and microanalytical techniques that have been systematically applied to address those issues. The R&D+I scope involves: (i) wave propagation techniques, (ii) image processing and optimization methods applied to scanning electron microscopy and thermal images, (iii) microanalytical characterization of Portland cement and aggregates of the region as well as (iv) the mitigation potential of pozzolanic and alkaline activated cements. Keywords: ARR; ASR; CHESF; Non-destructive and Micro analytical techniques. 71

73 15ICAAR2016_165 ELEMENTAL AND PHASE CHARACTERIZATION OF COARSE AGGREGATES COMMERCIALLY AVAILABLE FOR CONCRETE PRODUCTION IN THE BRAZILIAN NORTHEAST Sandro Marden Torres 1 ; Tiberio W. C. O. Andrade 2, Normando Perazzo Barbosa 1, Ricardo V. Gomes da Costa 1, Aerson M. Barreto 1. Marçal R.F.Lima Filho 1, Antônio.F. Leal 1. 1 Universidade Federal da Paraíba - UFPB, Paraíba, PB, BRAZIL 2 Universidade Federal de Pernambuco - UFPE, Pernambuco, PE, BRAZIL Coarse aggregates are the main component by mass of concrete mixes. They are often considered inert in many applications as far as concrete durability is concerned. When alkali aggregate reaction is expected, special attention must be given to the aggregates, cement blends and environment interactions. Most standards limit the total amount of alkali per cubic meter of concrete to only few kilograms. The Portland cement itself should contribute with not more than 1% of its mass. This is because of the widely known degrading and expansive mechanism involving the precipitation of AAR gels. Hence, it is important to account for certain chemical components and their crystal structure when assessing potential susceptibility to expansive mechanisms, as many minerals are acknowledge to have greater susceptibility to AAR. This paper aims to evaluate the elemental composition and the crystalline phases in several commercially available coarse aggregates from the Northeast area of Brazil. Samples from around fifty commercial producers were selected. The samples were ground and sieved through a 45μm sieve. The chemical composition was evaluated by means of x-ray florescence (WDS) and the crystalline phases by means of x-ray diffraction (Bruker D2-Lynx Eye detector). Considerations are given about the total alkaline silicate composition as well as for the type of each crystalline phases with respect to their silicate structure. Keywords: ARR; ASR; CHESF and Micro analytical techniques. 72

74 15ICAAR2016_179 ALKALI SILICA REACTION IN CONCRETE WITH GRANITE - LABORATORY TESTS AND REAL SERVICE CONDITIONS Kai Fischer¹, Liudvikas Urbonas, Detlef Heinz 1 Centre for Building Materials, Technische Universität München, Munich, GERMANY Damage to German concrete pavement by the alkali silica reaction has been repeatedly observed over the last two decades. Since certain slowly reacting aggregates are considered to be responsible for this damage they should be assessed in approved concrete performance tests before application in concrete pavement production. While the assessment of well-known alkali reactive aggregates in Germany provides reliable results, the assessment of granitic aggregates in concrete performance tests leads to unexpected indications of damaging ASR. In view of this, performance tests were carried out using top-layer pavement concrete compositions with granite in the coarse fractions and quartzitic sand. The results show that exposure to NaCl solutions unfavourably affects the alkali reactivity of the sand whereas the granite showed no indications of ASR. It is not known why this occurs in concrete with granite and quartzitic sand, but not with other slow reactive fine crystalline aggregates, e.g. greywacke. Investigations based on long time exposure of granite in the ASR mortar bar test reveal that the damage characteristics of ASR in granite particles differs clearly from that in fine crystalline slow reactive aggregates. Keywords: granite, performance test, alkali ingress 73

75 15ICAAR2016_200 THE ALKALI-SILICA REACTIVITY OF ANDESITIC RIVER AGGREGATES AND ASR MITIGATION EFFECT BY USING FINE FLY ASHES Kazuyuki Torii 1, Tetsuji Kubo 2, Chikao Sannoh 2, Maki Kanitani 2 1 Kanazawa University, Kakuma-machi, Kanazawa, JAPAN 2 Hokuriku Electric Power Co. Ltd, Ushijima-machi, Toyama, JAPAN In Toyama Prefecture in Japan, large numbers of concrete structures have been suffering from a combined damage caused by alkali silica reaction(asr) and/or the chloride-induced corrosion of reinforced concrete structure. The approach to solve this problem associated with durability of concrete is effective in the following methods; one the long-life of concrete structures by the repair and strengthening, the other the preventive countermeasures of concrete itself using fly ash. In the latter case, the standard use of fly ash cement with the replacement of more than 15% has been now recommended in all ready-mixed concrete mixtures from the economical and environmental point of view in this region. Recently, the production technique of very fine fly ash around 7 microns at average particle size has been successfully established at the Nanao-Ohta coal burning power plant in Hokuriku electric power company. It is enable to produce a highly-durable concrete, which is also related to produce a environmentally-friendly concrete matching with the regional demand. Accordingly, a joint collaborative industry-academia-government research committee, which is organized by the electric power company, the industrial association of ready-mixed concrete companies, the nation and local government and universities, has been set up in January In this paper, the results obtained from laboratory test using reactive river sand and gravel in Toyama prefecture, and its mitigating effect by classified fine fly ashes are introduced, which has been carried out in this committee for these 4 years. Furthermore, the influence of the use of classified fine fly ash on the environmental impact in the cement and concrete industry is also discussed. Keywords: ASR, volcanic aggregate, fly ash, assessment of ASR, mortar bar test 74

76 15ICAAR2016_203 EXACT EFFECTS OF TEMPERATURE INCREASE AND ALKALI BOOSTING IN CONCRETE PRISM TESTS WITH ALKALI WRAPPING Kazuo Yamada 1, Akihiro Tanaka 2, Satoshi Oda 2, Yasutaka Sagawa 2, Shoichi Ogawa 3, Takamasa Ochiai 4 1 National Institute for Environmental Studies, Research Center for Material Cycles and Wastes Management, Tsukuba, JAPAN 2 Kyushu University, Department of Civil and Structural Engineering, Fukuoka, JAPAN 3 Taiheiyo Consultant, Sales & Marketing Division, Tokyo, JAPAN 4 Chief Project Manager of Nuclear Safety Research Division, Mitsubishi Research Institute, Inc., JAPAN In a concrete prism test (CPT), expansion is accelerated by increasing temperature and alkali contents. Alkali leaching and drying are two problems with the CPT. Strict evaluation of their effects independently has been difficult. Therefore, to solve these problems, concrete prisms are wrapped in cloth wetted with a solution of alkali having the same concentration as the pore solution in the concrete. In this study, various Japanese reactive aggregates such as andesite containing opal and/or cristobalite, chert containing chalcedony, and several types of slow expansive aggregate containing cryptocrystalline quartz are examined. The results indicate that, depending on the aggregate type, expansion and mass gain differed on the basis of temperature and alkali content variation. Some of the alkali silica gel was lost from the prisms without causing expansion. A performance test result showed that accelerated test conditions of the CPT were modified depending on the reactivity of the aggregate. KEYWORDS: alkali wrapping, temperature, alkali content, expansion, mass gain, concrete prism test. 75

77 15ICAAR2016_206 CAN LIGHT WEIGHT AGGREGATE (LWA) LEAD TO HARMFUL ASR IN THE FIELD? Harald Justnes 1, Jan Lindgård 1, Marit Haugen 1, Eva Rodum 3, Bård Pedersen 3, Shon, Myung-soo 4 1 SINTEF Building and Infrastructure, Trondheim, NORWAY 3 Norwegian Public Roads Administration, Trondheim/Bergen, NORWAY 4 GS Engineering and Construction, Seoul, SOUTH KOREA Due to their silica content, most light weight aggregates (LWAs) are potentially reactive. Despite this, knowledge regarding pre-testing ASR properties of LWA and LWA concrete (LWAC) is lacking internationally. The accelerated mortar prism test shows that several LWAs can develop ASR, but it is uncertain if this will ever occur in the field. As a part of a Norwegian research project managed by SINTEF running from 2014 to 2018, one objective is to examine the ASR potential of LWA used in Norwegian concrete structures as basis for recommendation with respect to documentation and utilization of LWA and LWAC. Based on a literature study and results from accelerated tests, the consequence of potential ASR in LWAC is discussed. Keywords: Alkali-silica reaction (ASR), light weight aggregates (LWA), performance testing, field experience 76

78 15ICAAR2016_208 EVALUATION OF ALKALI-SILICA REACTION POTENTIAL OF MARGINAL AGGREGATES USING MINIATURE CONCRETE PRISM TEST (MCPT) Prasada R. Rangaraju 1*, Kaveh Afshinnia 2, Sai Sudhir R. Enugula 2 and Enamur R. Latifee 3 1 Professor, Glenn Dept. of Civil Engineering, Clemson University, Clemson, SC, USA 2 Graduate Student, Glenn Dept. of Civil Engineering, Clemson University, Clemson, SC, USA 3 Assistant Professor, Dept. of Civil Engineering, AUST, Dhaka, BANGLADESH Existing test methods to evaluate aggregate alkali-silica reactivity such as the accelerated mortar bar test (AMBT) and the concrete prism test (CPT) have shown deficiencies. Manipulating aggregate size by crushing coarse aggregate to meet the required gradation and high test temperature in the AMBT test are primary causes for its unreliability in accurately assessing aggregate reactivity, while alkali leaching from test specimens and long test duration required in the CPT test makes it somewhat impractical from routine evaluation. However, in terms of reliability of performance prediction in field, CPT test results have shown more reliability compared to that of the AMBT test method. This paper reports on a study to investigate Alkali-Silica Reaction (ASR) in concrete containing 42 different aggregates with a wide range of reactivity using a newly-developed test method called the Miniature Concrete Prism Test (MCPT) that overcomes the shortcomings of CPT and AMBT methods. MCPT results were correlated with the CPT and AMBT test results. Based on the findings from this study, it can be concluded that for assessing coarse aggregate reactivity, MPCT method provides equally reliable aggregate reactivity characterization as the CPT method in a much shorter duration of 56 days, instead of the 1-year test duration that is needed in the CPT method. However, the MCPT and CPT methods showed lesser correlation when characterizing the fine aggregate reactivity. The lack of agreement between MCPT and CPT in case of certain fine aggregates needs further investigation, along with calibration of all the threshold expansion values for all test methods with true field performance of aggregates. Key words: alkali-silica reaction, concrete expansion, miniature concrete prism test, concrete prism test, ASR gel 77

79 15ICAAR2016_225 A ROBUST TESTING PROTOCOL FOR THE ASSESSMENT OF ASR REACTIVITY OF CONCRETE Théodore Chappex 1,2, Lionel Sofia 1, Cyrille Dunant 1, Karen Scrivener 1 1 EPFL Ecole Polytechnique Fédérale de Lausanne, SWITZERLAND 2 TFB SA Technologie et Recherche pour le Béton, SWITZERLAND A number of ASR testing methods have been proposed over years but are generally found to be lacking. The use of blended cements makes the picture more complicated, as it was widely shown that mechanical and chemical properties of the concrete influence ASR behaviour. The Swiss Standard SIA 2042 performance test is analysed here and some inconsistencies are highlighted. In parallel, some inputs for a new protocol are proposed, based upon the acquired experience of the authors' laboratory and the research community. The new procedure aims to respect the chemical and mechanical properties of the tested concrete through the storage of samples in a solution matching the pore solution of the mix and a curing of the samples during 28 days before testing. Preliminary results are promising, showing a constant expansion rate over more than 400 days. The parameters of the test procedure have to be optimised and results have to be further compared with other test procedures in order to propose a robust testing protocol for ASR performance testing of blended cement concretes. Keywords: ASR assessment, aggregates, pore solution 78

80 15ICAAR2016_230 ASSESSMENT OF EXPANSION LEVELS OF VARIOUS MIXTURES WITH MULTIPLE EXPOSURE CONDITIONS (CONSECUTIVE FREEZE-THAW AND ASR CYCLES) Cihat Yüksel, Özge Andiç-Çakır, Kambiz Ramyar Ege University, Civil Engineering Department, Bornova, Izmir, TURKEY There are many test methods offered in standards and specifications for determining the potential damage due to individual durability problems (including alkali-silica reaction ASR) that may occur in concrete. However, in many cases, testing the exposure of concrete to only a single environmental exposure condition does not reflect the real conditions. Durability problems that act simultaneously or consecutively may lead to a greater damage than expected. In this study, a newly developed test method was adapted for determining the extent of expansion level due to consecutively acting freeze-thaw and ASR cycles. The specimens were subjected to frost action in accordance with the ASTM C666 standard and a total of 300 cycles were applied by using the rapid freezing in air and thawing in water (Procedure B) method. In order to promote the potential ASR in concrete prisms, RILEM AAR-4.1 method was followed at pre-specified time intervals and the total exposure time reached to 20 weeks. These multiple exposure conditions were investigated on four conventional mixtures including basalt and waste glass as aggregate. Besides, four mixtures of self-consolidating concrete with two different powder types and two different water/powder ratios were tested. According to the results, generally, expansion due to ASR occurred starting from the first weeks of exposure and frost action generated a triggering effect in the extent of expansion particularly in the late freeze-thaw cycles. The newly developed test method that simulates multiple durability problems for concrete seems to be promising. Keywords: freeze-thaw, alkali-silica reaction, concrete, multiple exposure conditions 79

81 15ICAAR2016_267 THE STUDY OF THE AZOREAN VOLCANIC AGGREGATES FROM THE POINT OF VIEW OF ALKALI SILICA REACTION Sara Medeiros 1, Isabel Fernandes 2,3, João Carlos Nunes 1, Benoit Fournier 4, António Santos Silva 5, Dora Soares 5, Violeta Ramos 3 1 Universidade dos Açores, Departamento de Geociências, Ponta Delgada, Azores, PORTUGAL 2 Universidade de Lisboa, Faculdade de Ciências, Departamento de Geologia, Lisboa, PORTUGAL 3 ICT, Institute of Earth Sciences, PORTUGAL 4 Université Laval, Québec, CANADA 5 LNEC - Laboratório Nacional de Engenharia Civil, Lisboa, PORTUGAL Volcanic rocks are the main source of concrete aggregates in Azores archipelago. In order to understand the reactivity of these rocks in this Portuguese territory, a study was implemented in the past three years to evaluate the potential alkali-reactivity of thirteen aggregates collected in these islands. For this study, a petrographic characterization and a chemical analysis were made on the rock samples and expansion tests were performed on the aggregates. The petrographic and the chemical analyses of the rocks confirmed that one of the samples contains free silica and three samples present interstitial volcanic glass. Microcrystalline quartz was confirmed by SEM/EDS as a secondary product filling the interstices of trachyte sample. The expansion tests show that the trachyte is the only aggregate with potential alkali-reactivity in the accelerated mortar-bar test. This paper presents the main results of eleven aggregates regarding the potential alkali-reactivity of the volcanic rocks from this archipelago. Keywords: ASR, volcanic rocks, petrography, expansion tests, Azores archipelago 80

82 15ICAAR2016_269 EVALUATION OF THE DELETERIOUS CHARACTER OF SILICEOUS AGGREGATES INCORPORATING SULFIDE MINERALS Andreia Rodrigues 1, Josée Duchesne 1*, Benoit Fournier 1 1 UNIVERSITÉ LAVAL, Centre de recherche sur les infrastructures en béton (CRIB) Québec, QC, CANADA Deterioration of concrete structures incorporating sulfide bearing aggregates has been reported in Trois-Rivières area, Québec, Canada. In this case, iron sulfide oxidation and internal sulfate attack were observed leading to excessive cracking of concrete within only a few years after construction. In order to evaluate the deleterious character of concrete aggregates incorporating sulfide minerals, an accelerated mortar bar test was developed. The manufacture of the mortar specimens is modeled on the ASTM C 1260 test method; however, the storage conditions were modified to maximize the oxidation reaction of sulfide minerals and related expansion. The first phase of the test thus consists in 90 days of storage at 80 C/80% RH, with 2 three-hour wetting cycles per week in a 6 vol % bleach solution. A number of different rock types were investigated in this study. However, the test was found to induce excessive expansion with alkali-silica reactive aggregates. Keywords: Sulfide-bearing minerals, performance testing, oxidation reaction, alkalisilica reaction 81

83 15 th ICAAR 2016 BRAZIL THEME 04 PREVENTIVE MEASURES

84 15ICAAR2016_035 EXPANSION OF CONCRETE CONTAINING REACTIVE RECLAIMED CONCRETE AGGREGATES OF DIFFERENT REACTIVITY AND COMPOSITION Matthew Piersanti 1, Medhat Shehata 1, Carole-Anne MacDonald 2, Stephen Senior 2 1 Ryerson University, Toronto, ON, CANADA 2 Ministry of Transportation, Toronto, ON, CANADA Through earlier studies, Recycled Concrete Aggregate (RCA) produced from reclaimed concrete material containing Alkali-Silica Reactive aggregate of high reactivity was found to cause expansion when used in new concrete. The level of preventive measures required to reduce the expansion to an acceptable level was higher for concrete with RCA than it was for the original concrete produced with the same aggregate. This finding motivated the authors to investigate if this would be the case if RCA was produced from concrete containing moderately reactive aggregates of different composition. The results confirmed the earlier finding although the expansion was generally lower than the earlier case with concrete containing highly reactive virgin aggregate or RCA. The testing carried out here supported earlier findings according to which the Concrete Microbar test can be a promising tool to evaluate reactivity of RCA. Keywords: reclaimed aggregate, alkali-silica reaction, supplementary cementing materials, concrete prism test, concrete microbar test 83

85 15ICAAR2016_036 ALKALI-CARBONATE REACTION: MECHANISM AND EFFECTS OF CEMENT ALKALI AND SUPPLEMENTARY CEMENTING MATERIALS Medhat Shehata 1, Steven Jagdat 2, Mohamed Lachemi 1, Chris Rogers 3 1 Department of Civil Engineering, Ryerson University, Toronto, ON, CANADA 2 Golder Associates, ON, CANADA 3 Post Office Box 185, Beeton, ON, CANADA Alkali carbonate reaction (ACR) is a reaction between alkalis in pore solution of concrete and some types of dolomitic limestone coarse aggregate of specific chemical and mineralogical composition. It has been reported that low-alkali Portland cement and some types of Supplementary Cementing Materials (SCM) were not effective in mitigating the damage. This study investigated the effect of a wide range of SCM on expansion of concrete prisms (CSA A A) containing alkalicarbonate reactive aggregate from Kingston, Ontario, Canada. The results showed that while some blends were effective in reducing the rate of expansion, the expansion values at two years were higher than the 2-year expansion limit of 0.040% l/l. Low-alkali Portland cement of Na 2 O e of 0.60 wt% or combinations of SCM and Portland cement of Na 2 O e of 0.80 wt% were not effective in meeting the expansion limit at 2 years. However, 15 wt% metakaolin was the most effective material to reduce the rate of expansion. Keywords: Alkalies, alkali-carbonate reaction, blast-furnace slag, cement, dedolomitization, dolomitic limestone, expansion, fly ash, metakaolin, silica fume, supplementary cementing materials, ternary blends. 84

86 15ICAAR2016_039 AN EXAMINATION OF AAR MITIGATION MEASURES USING FLY ASH Shigenobu Iguchi 1, Yoshinori Matsuda 1, Daisuke Tsukishima 1 1 East Japan Railway Company, Structural Engineering Center, Tokyo, JAPAN In the neighborhood of Niigata Station in the center of Niigata-City, construction is underway to construct new railroad continuous viaducts. However, in the neighborhood of Niigata Station, it is difficult to obtain aggregates that are nonreactive. Thus, we decided to build these viaducts using highly reactive Highlyreactive aggregates by providing appropriate Alkali-Aggregate Reaction (AAR) mitigation measures. We considered whether we controlled AAR using fly ash. At first we identified a highly-reactive aggregate among available aggregates near Niigata Station. We changed the mixed ratio of the highly-reactive aggregates and made concrete in which we substituted 10%, 20%, 30%, 40% of cement with fly ash and evaluated the AAR characteristics. As a result, we were able to control expansion when 40% of the highly-reactive aggregates were used, by substituting fly ash for at least 20% of the cement. In addition, we examined the strength properties and construction characteristics of the concrete of this combination and confirmed that it was combination suitable for use. Therefore, using concrete of this mix design, the new railroad viaducts were constructed. Keywords: fly ash, AAR mitigation measures, Highly-reactive aggregates, coefficient of expansion, railroad viaducts 85

87 15ICAAR2016_082 STUDY ON ASR EXPANSION AND ITS SUPPRESSING MEASURES OF SELF-COMPACTING CONCRETE USING SEA WATER Takashi Habuchi 1, Yuichiro Kawabata 2,3, Naoya Kawamura 4, Ryoichi Tanaka 1, Jun Kutsuna 1, Toru Yamaji 2, Osamu Kiyomiya 5 1 Toa Corporation, Yokohama, JAPAN 2 Port and Airport Research Institute, Yokosuka, JAPAN 3 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la-Vallée, FRANCE 4 National Institute for Land and Infrastructure Management, Yokosuka, JAPAN 5 Waseda University, Tokyo, JAPAN The authors have carried out the development of self-compacting concrete using sea water. When utilizing this concrete, ASR expansion due to alkali supplied from sea water should be concerned. From these backgrounds, the authors have conducted the ASR expansion test for concrete specimens. As the preventive measure to suppress the ASR expansion, replacement of cement by BFS was used. Through the expansion test in the laboratory for about two years, ASR expansions of specimens were measured. SEM-EDS analyses were also carried out after the test. As the results, it is confirmed that the replacement of cement by sufficient amount of BFS is effective to supress the ASR expansion for each test. The SEM-EDS analyses suggest that the reduction in alkalinity due to alkali uptake in C-S-H gel with lower Ca/Si ratio by replacing cement with slag can be taken into account even in the case of concrete using sea water. Keywords: concrete using sea water, expansion test for ASR expansion, suppressing measures, replacement level by blast furnace slag 86

88 15ICAAR2016_109 POTENTIAL OF METAKAOLIN IN MITIGATING EXPANSIONS OF ASR IN ACCELERATED TESTS Nicole P. Hasparyk 1, Guilherme Gallo 2, Tibério Andrade 3, Tatiane O. Santos 4 1 ELETROBRAS Furnas, Gerência de Pesquisa, Serviços e Inovação Tecnológica, Goiânia, GO, BRAZIL 2 Metacaulim do Brasil Indústria e Comércio Ltda, São Paulo, SP, BRAZIL 3 Tecomat, Recife, PE, BRAZIL 4 Universidade Federal de Goiás, Institute of Physics, Goiânia, GO, BRAZIL This paper presents the results of an experimental research concerning the potential of the admixture metakaolin in mitigating expansions from alkali-silica reaction. Brazilian reactive aggregates were selected for this purpose and accelerated mortar bar tests (AMBT) were performed in order to evaluate ASR expansions over time, and up to 30 test-days. Tests were conducted with a variation on metakaolin contents in order to achieve the optimum content for each situation. Mortar bars were immersed in sodium hydroxide 1N solution at temperature of 80 C. After expansion tests, some microstructural analyses by scanning electron microscope were also undergone to investigate internal ASR products formed and also to search for differences between tested samples. This paper indicates that metakaolin admixture is able to mitigate ASR expansions, depending on the content tested. Keywords: Alkali-silica reaction, metakaolin, mitigation, expansion, microstructure. 87

89 15ICAAR2016_111 INFLUENCE OF SUGARCANE BAGASSE ASH IN THE EXPANSIONS OF MORTARS AFFECTED BY ALKALI-SILICA REACTION Marcia F. Fortes Aguas 1, Eduardo de M. R. Fairbairn 1, Romildo D. Toledo Filho 1, Nicole P. Hasparyk 2, Guilherme C. Cordeiro 3 1 Universidade Federal do Rio de Janeiro, COPPE, Rio de Janeiro, RJ, BRAZIL 2 ELETROBRAS Furnas, Gerência de Pesquisa, Serviços e Inovação Tecnológica, Goiânia, GO, BRAZIL 3 Universidade Estadual do Norte Fluminense, Campos dos Goytacases, RJ, BRAZIL This work presents the results of an experimental research concerning the influence of the partial replacement of cement by sugarcane bagasse ash (SCBA) in mortars subjected to alkali-aggregate reaction (AAR). Adaptations were made in a standard test of long term expansion to conduct evaluations and comparisons of expansions measurements of mortar cylindrical specimens produced with cement mass substitution of 0%, 8% and 12% bagasse ash sugarcane and 8% also by silica fume. Expansion tests were conducted using equipment (robot), designed and manufactured to perform automatic reading of volumetric deformations in free expansion tests. After curing for 28 days, the specimens of each mixture were maintained at temperature of C, immersed in sodium hydroxide 1N solution for a period of 425 days. The mortar with substitution of 8% silica fume did not provide expansions from 45 days mitigating ASR expansion. The reference mortar (0%) and those with substitution of 8% and 12% of cement per sugarcane bagasse ash showed high expansions and about 0.20%, 0.35% and 0.19% of average volumetric expansion at 360 days of testing, respectively, indicating that under the conditions adopted sugarcane bagasse ash cannot mitigate ASR. The anisotropic behavior of expansions could be found in this research from major expansions measurements than 0.03%. The anisotropy factor, ratio between longitudinal and diametrical expansions steps, with no addition varies from 1.3 to 2.2 respectively to the 275 days and 425 days after immersion in the alkaline solution. The factors anisotropy of mortars with substitution of 8% and 12% of cement per sugarcane bagasse ash clearly show different values, with variations between 0.7 and 1.1. Keywords: Alkali-silica reaction, sugarcane bagasse ash, volumetric deformations. 88

90 15ICAAR2016_131 FLY ASH TO PREVENT ASR WITH SLOWLY-REACTIVE AGGREGATES IN PORTUGAL João Custódio 1, Felipe Río Iglesias 2, Óscar Herrero Domínguez 2, António Santos Silva 1, António Bettencourt Ribeiro 1, Dória Costa 1 1 LNEC National Laboratory for Civil Engineering, Lisbon, PORTUGAL 2 Endesa Generación, S.A., Madrid, SPAIN Alkali-Silica Reaction (ASR) is recognised as a durability problem in last years in Portugal. Several cases have been identified in bridges and dams, mainly due to the use of potentially slowly-alkali reactive granitic aggregates. These granitic aggregates are still being used in new constructions in Portugal, and particularly in large concrete dams. The Portuguese regulation on ASR refers the need of using supplementary cementitious materials (e.g. fly ash, granulated blast furnace slag) to counteract the pernicious effects due to ASR development. This paper describes the methodology applied in the evaluation of concrete granitic aggregates to be used in a Portuguese hydroelectric project. The results obtained by modified concrete prism tests, with fly ashes from different sources and cement and sand replacement levels, and incorporation two alkali boosting levels, are presented and discussed. Keywords: ASR, prevention, fly ash, concrete, expansion test-methods 89

91 15ICAAR2016_139 A REVIEW ON USING CALCINED CLAYS TO MITIGATE ALKALI-SILICA REACTION Chang Li¹, Jason H. Ideker 1, Thano Drimalas 2, Matthew P. Adams 3 1 Oregon State University, Corvallis, OR, USA 2 The University of Texas at Austin, Austin, TX, USA 3 New Jersey Institute of Technology, Newark, NY, USA Metakaolin, a commonly used calcined clay, has been investigated extensively for its role to mitigate alkali-silica reaction (ASR) in concrete. It has been proven to be a useful supplementary cementitious material (SCM) that is capable of effectively mitigating ASR by reducing the alkalinity in the pore solution of paste, mortar and concrete as well as binding available alkalis in the mixture. However, previous research indicated that the efficacy of calcined clays in mitigating ASR can vary significantly due to differences in quality and source. This paper reviews current studies on the factors that could influence the pozzolanic reactivity of calcined clays from different sources as well as their efficacy in mitigating ASR. In addition, test results from accelerated mortar bar tests (AMBT), concrete prism test (CPT) were evaluated for their accuracy by comparing to the results of the field exposure block test. The review was focused on: the impact of the manufacturing process - specifically calcination temperature, the mineral phase composition of calcined clays, and the pozzolanic reactivity of these minerals. The effect of the composition of calcined clays, especially alumina and alkalis, on the efficacy of alkali binding ability and ASR mitigation as well as suggested replacement levels for ASR mitigation based on composition and mineral phases of calcined clays are also presented along with the correlation of lab tests to the exposure concrete block test. Keywords: calcined clay, ASR, aluminium, pozzolanic reactivity, 90

92 15ICAAR2016_141 OBSERVATIONS ON USING EXPANDED CLAY TO CONTROL EXPANSION CAUSED BY ALKALI-SILICA REACTION Chang Li 1*, Jason H. Ideker 1, Michael D. A. Thomas 2 1 Oregon State University, Corvallis, OR, USA 2 University of New Brunswick, Fredericton, NB, CANADA Previous research indicated that mortar and concrete mixtures showed less expansion caused by alkali-silica reaction (ASR) when fine lightweight aggregates (FLWAs) were incorporated into the mixtures. However, these results were limited, and conflicting mechanisms and theories exist. Therefore, a research program was initiated to explore the mechanism(s) by which FLWA may mitigate ASR. In this program, one commonly used FLWA, an expanded clay, was incorporated. Tests methods including the ASTM C 289 test, the ASTM C 1260 test and the ASTM C 1293 test were used to investigate the effectiveness of the expanded clay in ASR mitigation when combined with aggregates of known reactivity. In these mixtures, fine normal weight aggregate were replaced by the expanded clay at 25% and 50% by volume, which are the replacement levels typically used for internal curing. Preliminary results indicated that the expanded clay showed effectiveness in mitigating ASR in the ASTM C 1260 test when they were in either pre-wetted or oven-dried conditions. However, more expansion was observed when the expanded clay was pre-wetted. Pore solution analysis results indicated that the expanded clay in the mixture with Spratt could reduce the alkalinity of the pore solution, especially the mixture showed reduction in alkalinity even at early ages (7 days to 28 days). SEM analysis revealed infilling reaction products were deposited into the pores of the expanded clay. More investigation is still needed to understand the composition of the reaction products deposited into the pores of the expanded clay. Keywords: ASR, expanded clay, ASTM, expansion, infilling reaction product 91

93 15ICAAR2016_167 EFFECT OF THE USE OF AAC IN MITIGATING THE ALKALI- AGGREGATE REACTION Kelly Cristiane Gomes 1, Sandro Marden Torres 2, Aluisio Caldas e Silva 3, José Gonçalves Diniz Neto 2, Kathelynne Lacerda Marques de Melo 2, Eduardo Jorge de Albuquerque Bezerra Filho 2 1 Department of Renewable Energy Engineering - Federal University of Paraiba, Paraiba, PB, BRAZIL 2 Department of Technology- Federal University of Paraiba, Paraiba, PB, BRAZIL 3 CHESF-PE Companhia Hidroelétrica do São Francisco, Pernambuco, PE, BRAZIL Alkali-aggregate reaction is a pathology directly linked to interactions between solubilized alkali hydroxides in the pore structure concrete and other chemical species from aggregates. In the presence of excessive water, these chemical interactions lead to the precipitation of gel-like phases within aggregates, pasteaggregate interface and cement matrix, causing expansion due to internal pressure in concretes that can promote disruption. It appears that the volume expansion of silica gels tends to have a maximum at the total dissolved silica. Both alkali and silica are needed to chemically stabilise alkaline activated cements (AAC-geopolymers). Therefore, this study aims to evaluate the potential use of geopolymers as mitigating agent of AAR. Four formulations were carried out in the study, three metakaolin based AAC were synthesized with different alkali types (100% sodium silicate, 100% potassium silicate and 50% of sodium silicate and 50% potassium silicate). Portland cement mortar (CPV-ARI) was used as reference. Reactive aggregate (Pyrex) was used as aggregate in all mortars. All materials and samples were characterized by means of their chemical, mineralogical and microstructural properties. Prismatic mortars bars (25x25x285 mm) were cast and tested performed by the accelerated expansion method according to NBR and Scanning Electron Microscopy, Ultrasound analysis and X-ray Diffraction were used as complementary testing. Considerations are given with regards to the potential use of AAC as mitigating agent for AAR. Keywords: AAC, Geopolymer, AAR, Mitigating Agent. 92

94 15ICAAR2016_176 THRESHOLD EFFECT IN ALKALI-SILICA REACTION INHIBITION ON MICRO-MORTARS AND MORTARS WITH LIOH Angélique Rousselet 1,2, Vincent Thiéry 1,2, David Bulteel 1,2 1 Mines Douai, LGCgE-GCE, F Douai, FRANCE 2 Univ. Lille, F Lille, FRANCE Lithium compounds can mitigate alkali-silica reaction (ASR). The aim of this study was to investigate the potential occurrence of the threshold effect (previously observed in model reactor tests) in an actual cementitious matrix (mortars) and to improve the understanding of lithium role on the alteration mechanism of ASR. This study is based on the expansion tests of micro-mortar bars (1 1 4cm 3 ) at 80 C, 100% R.H. and mortar bars (4 4 16cm 3 ) at 60 C, 100% R.H. Mixes were made using a flint aggregate, an OPC and lithium and sodium hydroxides. ToF-SIMS was used to determine the location of lithium in mortar bars only. The threshold effect was observed in micro-mortar and mortar bars, respectively at a Li/Na eq ratio of 0.20 and Observations of polished sections of mortar bars in ToF-SIMS reveal that lithium is within the flint particles when the reaction is inhibited; this questions the mechanism of a protection barrier inhibiting ASR. Keywords: ASR, inhibition, lithium hydroxide, flint aggregate 93

95 15ICAAR2016_210 INFLUENCE OF ALKALI CONTENT OF CEMENT ON MECHANICAL AND DURABILITY PERFORMANCE OF UHPC Prasada R. Rangaraju 1*, Zhengqi Li 2, Kaveh Afshinnia 2 1 Professor, Glenn Dept. of Civil Engineering, Clemson University, Clemson, SC, USA 2 Graduate Student, Glenn Dept. of Civil Engineering, Clemson University, Clemson, SC, USA Ultra-high performance concrete (UHPC) is characterized by high cement content and low water-to-cementitious materials ratio, which presents an ideal scenario for potential localized alkali-silica reaction (ASR) to occur, particularly if the aggregate is reactive and the cement is rich in alkalis. The alkali content of the cement can also be a sensitive factor affecting fresh and hardened properties of concrete. However, there is limited information available in literature on the influence of cement alkalinity on properties of UHPC. In this paper, workability, setting time, mechanical and durability properties of the high performance cementitious mortar (HPCM) fraction of UHPC were studied as a function of the alkali content of cement ranging from 0.49% to 0.88% Na 2 Oeq in presence and absence of fly ash. For HPCMs with and without fly ash, an increase in alkali content of cement reduced the workability and compressive strength. The final setting time was prolonged as the alkali content increased. Rapid and significant expansion due to ASR was observed in HPCM without fly ash along with loss in both compressive strength and flexural strength of HPCM, as the alkali content of cement increased. In HPCM mixtures with fly ash, no significant expansion due to ASR or significant loss in compressive/flexural strength was observed, regardless of the alkali content of the cement. Keywords: UHPC, alkali content of cement, workability, alkali-silica reaction, compressive strength, flexural strength 94

96 15ICAAR2016_268 EFFECTIVENESS OF ALKALI-ACTIVATED SLAG BASED BINDERS AND FLY-ASH BASED GEOPOLYMERS AGAINST ALKALI SILICA REACTION (ASR) Charles Lafrenière 1, Josée Duchesne 1*, Benoit Fournier 1 1 UNIVERSITÉ LAVAL, Centre de Recherche sur les Infrastructures en Béton (CRIB) Québec, QC, CANADA Cement-free alkali-activated binders and geopolymers are activated by concentrated alkaline solution, thus raising questions in the presence of reactive aggregates. Alkali-activated slag-based binders and fly ash- based geopolymers were subjected to accelerated mortar bar and concrete prism testing, respectively, using three different reactive aggregates and a 8M NaOH alkaline activator solution. Alkali-activated slag-based mortars behaved differently depending on the reactive aggregate. Mortars incorporating a moderately reactive aggregate suffered 14-day expansion below 0.10%, while those made with a highly reactive siliceous limestone showed a rapid expansion ( 0.4% after 3 days) with slight increase afterwards. All fly ash-based geopolymer concretes suffered low expansion until about 40 weeks and then the expansion rate increased to reach values up to 3 times those measured on control (cement) concretes at 78 weeks. More fundamental testing is necessary to better understand the behavior of alkali-activated binders and geopolymers in the presence of reactive aggregates. Keywords: Alkali silica reactivity, alkali-activated slag cements, fly-ash based geopolymers, expansion. 95

97 15ICAAR2016_270 INFLUENCE OF SUPERPLASTICIZERS ADMIXTURES IN THE ALKALI- SILICA REACTION Cláudia Flaviana C. da Silva 1*, António Santos Silva 2, Arnaldo M. P. Carneiro 3 1 Universidade Federal de Pernambuco, BRASIL 2 Laboratório Nacional de Engenharia Civil, PORTUGAL 3 Universidade Federal de Pernambuco, BRASIL The alkali-silica reaction (ASR) consists of the reactive process in which aggregates containing reactive silica constituents react with alkalis and hydroxyl ions present in cement pore solution. It is suspected that some superplasticizers admixtures can contribute to the increase in concrete alkalinity. Literature presents some contradictory results about its influence on ASR. In this work the influence of superplasticizers admixtures in mortars prepared with pozzolanic admixtures was evaluated by accelerated mortar-bar tests and atomic absorption spectrophotometry. In the pozzolanic mixes the cement was replaced by 15% (weight %) of metakaolin or silica fume. Three superplasticizers admixtures (melamine, lignosulfonate and naphthalene) were utilized in three levels. The results show the mortars with the melamine based superplasticizers presented the lower content of soluble alkali and expansion. It is concluded that this admixture could be the most indicated for use with MK, or SF, to the inhibition of the ASR, considering the aggregate tested. Keywords: superplasticizers, alkali-aggregate reaction, metakaolin, silica fume, mitigation. 96

98 15ICAAR2016_271 COMPARATIVE FIELD AND LABORATORY INVESTIGATIONS ON THE USE OF SUPPLEMENTARY CEMENTING MATERIALS (SCMs) TO CONTROL ALKALI-SILICA REACTION (ASR) IN CONCRETE Benoit Fournier¹, Raymond Chevrier 2, Alain Bilodeau 2, Pierre-Claver Nkinamubanzi 3 and Nabil Bouzoubaa 2 1 Département de géologie et de génie géologie, Université Laval, Québec, Québec, CANADA 2 CANMET, Natural Resources Canada, Limebank Road, Ottawa, ON, CANADA 3 National Research Council of Canada, Ottawa, Ontario, CANADA ABSTRACT A comparative field and laboratory research program was initiated at CANMET in 1991 for evaluating the efficacy of laboratory tests for reliably evaluating the potential alkali-reactivity of concrete aggregates and the efficacy of SCMs in preventing ASR. Air-entrained concrete mixtures were made with a variety of reactive aggregates and SCMs, from which test prisms and exposure blocks were cast. The various combinations were also tested in the Accelerated Mortar Bar Test. The concrete prism and accelerated mortar bar tests were effective in predicting the potential alkali-reactivity of the aggregates selected. Concrete prism testing in accordance with CSA A A reliably predicts the efficacy of SCMs for preventing short term exposure block expansions (~10 year); however, the correlation is decreasing afterwards. Extending the testing period in the control laboratory condition or exposing concrete prisms to a source of external alkalis can sometimes improve correlations, but the beneficial effect varies from one aggregate and one SCM to another. Key words: Alkali-silica reaction, supplementary cementing materials, concrete prism test, accelerated mortar bar test, field exposure. 97

99 15 th ICAAR 2016 BRAZIL THEME 05 DIAGNOSIS AND ASSESSMENT

100 15ICAAR2016_012 CREEP BEHAVIOUR OF ALKALI-SILICA REACTION DAMAGED CONCRETE WITH SLOW-REACTING AGGREGATES Oliver Mielich 1, Hasan Özkan 1, Hans W. Reinhardt 2 1 Materials Testing Institute University of Stuttgart, Otto-Graf-Institute, GERMANY 2 Department of Construction Materials, University of Stuttgart, GERMANY ABSTRACT Concrete structures damaged by alkali-silica reaction (ASR) remain in use in several cases for a long period of time. To calculate the residual strength and the deformation of ASR damaged structures knowledge of the strength, elastic modulus and creep are required. Concretes with four types of slow-reacting aggregates have been exposed in German fog chamber at 40 C for 560 days. The aggregates present different characteristics and differ in ASR susceptibility. Four aggregates were selected for his research, a greywacke, two quartz porphyries and a crushed gravel from the Upper Rhine valley. Compressive strength, static modulus of elasticity as well as creep and shrinkage deformations were measured at fixed intervals. It is shown that static modulus of elasticity is significantly more affected by ASR than compressive strength. Furthermore, ASR affects the creep behaviour, which depends strongly of the kinetic rate (evolution) of the chemical reaction. Keywords: alkali-silica reaction, creep, shrinkage, mechanical properties 99

101 15ICAAR2016_022 THOROUGH EVALUATION OF BRIDGE COLUMNS AFFECTED BY ALKALI-SILICA REACTION (ASR) Leandro Sanchez 1, Benoit Fournier 2, Josée Bastien 2, Denis Mitchell 3, Martin Noel 1 1 University of Ottawa, Ottawa, ON, CANADA 2 Université Laval, Québec, QC, CANADA 3 McGill University, Montréal, QC, CANADA Robert-Bourassa/Charest viaduct (Quebec, Canada) was a bridge structure severely affected by alkali-silica reaction (ASR). Over the years, several inspection surveys and analyses confirmed that the coarse aggregate used in the construction (local siliceous limestone) was alkali-reactive and for many years monitoring and laboratory tests were carried out on the different elements of the structure. In , the viaduct was demolished, which gave the opportunity of obtaining two 3- meter sections of the reinforced columns, one coming from an exposed site and the other from a non-exposed one (i.e. under the bridge deck). This paper presents the results of the mechanical evaluation as well as the appraisal of the stress-state of the stirrups of both concrete columns. Results show that damage varies according to the columns exposure conditions and coring direction. Concerns may arise regarding the potential for stirrups yielding in the field. Keywords: Alkali-aggregate reaction; structural implications; aging infrastructure; concrete structures. 100

102 5ICAAR2016_024 THE USE OF THE DAMAGE RATING INDEX (DRI) FOR THE CONDITION ASSESSMENT OF AGING DISTRESSED CONCRETE Leandro Sanchez 1, Benoit Fournier 2, Marc Jolin 2, Josée Bastien 2, Denis Mitchell 3, Martin Noel 1 1 University of Ottawa, Ottawa, ON, CANADA 2 Université Laval, Québec, QC, CANADA 3 McGill University, Montréal, QC, CANADA This paper presents the results of the condition assessment of twenty concrete mixtures incorporating ten different reactive aggregates through the Damage Rating Index (DRI), a microscopic and semi-quantitative petrographic tool, with the aim of verifying AAR distress development as a function of the specimen s expansion. The DRI was found to provide a reliable assessment of the degree of damage in the concretes samples incorporating reactive fine or coarse aggregates. An envelope of DRI damage assessments values against the expansion level of the affected materials is proposed. Moreover, the evaluation of a damaged aging concrete structures showed that the DRI is a powerful tool to provide the condition assessment of AARdistressed concrete infrastructure conditions. Keywords: alkali-aggregate reaction, crack detection, degradation, damage rating index, durability 101

103 5ICAAR2016_025 THOROUGH CHARACTERIZATION OF CONCRETE DAMAGE CAUSED BY AAR THROUGH THE USE OF A MULTI-LEVEL APPROACH Leandro Sanchez 1*, Benoit Fournier 2, Marc Jolin 2, Josée Bastien 2, Denis Mitchell 3, Martin Noel 1 1 University of Ottawa, Ottawa, ON, CANADA 2 Université Laval, Québec, QC, CANADA 3 McGill University, Montréal, QC, CANADA Over the last few years, comprehensive management programs for the diagnosis and prognosis of AAR in aging concrete structures were developed in North America, based on a series of laboratory test procedures. Although promising, these lab-procedures presented several parameters whose impacts were not completely understood, which significantly reduced their applicability for the appraisal of deteriorated concrete structures in service. In this context, it has been suggested that two lab-procedures, namely the Stiffness Damage Test (SDT) and the Damage Rating Index (DRI) could reliably assess the condition of concrete affected by AAR. However, the full multi-level characterization of AAR damage through the coupling of the prior tools has never been treated so far. This paper presents the overall assessment of 35 MPa concrete specimens incorporating a wide range of reactive aggregate types/natures, and presenting different AAR distress degrees (i.e. expansion levels from 0.05 to 0.30%). Keywords: damage assessment, stiffness damage test (SDT), damage rating index (DRI), multi-level approach. 102

104 5ICAAR2016_046 DEVELOPMENT AND TESTING OF NDE MOCKUP SPECIMENS WITH ASR Eric R. Giannini 1, Patrice Rivard 2, Serge Apedovi Kodjo 2, Stepahnie G. Wood 1, Maria Guimaraes 3, 1 The University of Alabama, Tuscaloosa, AL, UNITED STATES OF AMERICA 2 Université de Sherbrooke, Sherbrooke, QC, CANADA 3 Electric Power Research Institute, Charlotte, NC, UNITED STATES OF AMERICA A number of experimental NDT methods have provided promising results in evaluating small laboratory samples, often constructed of mortar and placed in severe environmental conditions. However attempts to apply these methods to larger-scale concrete specimens more dimensionally representative of concrete structures in the field have been more limited. A major challenge in validating NDT techniques for evaluating the severity of ASR-induced distress has been the lack of common specimens conditioned to a known level of deterioration. To address this problem, the Electric Power Research Institute (EPRI) and The University of Alabama partnered to fabricate and condition larger-scale plain concrete slabs to serve as common mockup specimens that were then made available to researchers to test the viability of their NDT methods. A research team from Université de Sherbrooke conducted non-linear acoustic testing (time-shift method) on the specimens at the EPRI NDE laboratories. The time-shift method was utilized to characterize distress in the specimens and was able to distinguish between specimens with varying degrees of expansion. This paper highlights the greater potential of nonlinear acoustics for assessing ASR damage. Keywords: Nondestructive testing, alkali-silica reaction, ultrasonic pulse velocity, nonlinear acoustics, damage assessment 103

105 15ICAAR2016_050 DIAGNOSIS OF AAR AND DEF: COMPARISON OF RESIDUAL EXPANSION, STIFFNESS DAMAGE TEST AND DAMAGE RATING INDEX Renaud-Pierre Martin 1, Leandro Sanchez 2, Benoît Fournier 3, François Toutlemonde 1, 1 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la-Vallée Cedex 2, FRANCE 2 University of Ottawa, ON, CANADA 3 Laval University, Geology and Geological Engineering Department, Quebec, QC, CANADA Aging concrete structures affected by internal swelling reactions (ISR) may be quite difficult to manage. Over the last few years, several tools were developed in order to provide diagnostic assessment of aging concrete structures, especially those affected by alkali-aggregate reaction (AAR). Among those tools, the Stiffness Damage Test (SDT), Damage Rating Index (DRI) and Residual Expansion (RE) seem to have a great potential. However, the comprehensive character of the tools in assessing different mechanisms other than AAR was barely verified, which reduces their use in engineering purposes. This paper presents the results of a study where the above three tools were used for assessing the condition of a concrete structural element damaged by ASR+DEF coupling. Results show that the three procedures were similarly capable of providing a diagnosis quantitative estimate of the expansion attained by the concrete. Finally, although theoretically different, the test procedures seem to have a somehow complementary character, and could potentially be used together in engineering practices. Keywords: Diagnosis, AAR, DEF, Stiffness Damage Test, Damage Rating Index, Residual expansion test 104

106 5ICAAR2016_066 INVESTIGATION AND ASSESSMENT OF ALKALI AGGREGATE REACTION (AAR) IN THE PIRAPORA DAM Marcela B.S. Sollero 1*, Lilian Q.G. Baima 1, Heloisa Bolorino 1 1 CONCREMAT Engenharia e Tecnologia S.A., São Paulo, SP, BRAZIL The increase in understanding of the mechanisms and effects of alkali aggregate reaction (AAR) in concrete since the 1990s has allowed for a correlation between visual symptoms existing in the Pirapora Dam and AAR monitored over the years. Due to the significant evolution of the surface map cracking and subparallel cracks presented, a study was developed to characterize the concrete of the Dam and the expansive reactions resulting from AAR sulphate contribution that affect the Dam. This study includes the mapping of the anomalies and testing, as the evaluation of the physical and mechanical properties of concrete, petrographic analysis, and determination of the alkali content and residual expansion of samples. It was possible to assess the evolution of the expansive reactions in concrete and the Dam durability conditions, taking into account the environmental conditions and factors that are important for the determination of the most appropriate mitigation and recovery measures for the structure. Keywords: alkali aggregate reaction, petrography, gravity dam 105

107 15ICAAR2016_070 DEVELOPMENT OF AN ELECTROCHEMICAL MIGRATION CELL FOR LITHIUM IMPREGNATION LABORATORY ASSESSMENT Juan Lizarazo-Marriaga 1, Julián Silva 1, Juan Lozano 1 & Leonardo Fonseca 1 1 Universidad Nacional de Colombia Bogotá, COLOMBIA The use of lithium compounds has a positive effect in mitigating the alkali-silica reaction (ASR) in concrete. This effect has been observed on hardened concrete when it is impregnated with lithium compounds with the help of electrical methods. This paper proposes an electrochemical migration cell and an experimental setup, as an approach for simulating lithium compound treatments on hardened concrete under laboratory conditions. Experiments were carried out in which mortar bars, cast in ASTM C490 molds, underwent an electrochemical lithium treatment and the accelerated ASTM C1260 mortar-bar method. Using a potential reactive aggregate, one set of reference bars were assessed according to the ASTM C1260 standard, whereas another set of bars underwent an electrochemical lithium impregnation treatment with the help of the migration cell designed for this purpose. Results indicate that the electrochemical cell was effective during the lithium-impregnation and the treatment reduced the effects of the ASR reaction in the mortar bars. Keywords: alkali silica reaction (ASR), electrochemical lithium impregnation, lithium migration, electrochemical migration cell. 106

108 5ICAAR2016_074 APPLICATION OF PROGNOSIS AND DIAGNOSIS TECHNIQUES OF ASR FOR A HISTORIC STRUCTURE Anthony F. Bentivegna 1, Jason H. Ideker 2 1 CTLGroup, Skokie, IL, USA 2 Private Consultant, Corvallis, OR, USA The Orchard Beach Bathhouse and promenade was a federally-funded public works project conceived during the Great Depression of the 1930s. Since its construction, the bathhouse has aged and suffered deterioration due to alkali-silica reaction (ASR), freeze-thaw cycling, and corrosion. The works summarized in this paper gives an overview of testing techniques for assessing the amount of deterioration due to ASR and the potential for continued deterioration. Over 400 cores were extracted from the historic concrete structure, although only a small subset will be reported in this paper. These cores were evaluated for typical mechanical properties and petrographic examination according to ASTM C856. In addition to these routine tests, damage rating index (DRI), stiffness damage testing (SDT), residual expansion testing, hot-water extraction of water soluble alkalis, and in-situ monitoring of crack propagation and expansion measurements were implemented on this structure. The findings of these techniques indicated the primary cause of deterioration was due to freeze-thaw deterioration and corrosion, although active ASR was observed. Keywords: alkali-silica reaction, petrography, damage rating index, stiffness damage testing, water-soluble alkalis 107

109 5ICAAR2016_080 ASSESSMENT OF SEVERELY ASR DAMAGED BRIDGES: FROM DIAGNOSIS TO STRUCTURAL EFFECTS Ricardo Antonio Barbosa¹, Søren Gustenhoff Hansen 2, Kurt Kielsgaard Hansen 1, Linh Cao Hoang 1, Bent Grelk 1,3, Iben Maag 4 1 Technical University of Denmark, Kongens Lyngby, DENMARK 2 University of Southern Denmark, Odense, DENMARK 3 Grelk Consult, Copenhagen, DENMARK 4 The Danish Road Directorate, Copenhagen, DENMARK During the last decade an increasing number of bridges are becoming severely deteriorated due to alkali-silica reaction (ASR) in Denmark. Some bridges have already been demolished due to lack of knowledge on the residual load carrying capacity. The deterioration of concrete by ASR has been widely documented. The majority of the experimental data are based on relatively small scale laboratory specimens accelerated by various exposure conditions. Research on assessment and influence of severely ASR deterioration on the material properties and residual load carrying capacity of real-life structures is unfortunately limited. This paper presents an overview and discussion of the Danish experiences with assessment of the residual load carrying capacity of severely non-shear reinforced ASR damaged bridges. The discussion is supported by experimental data acquired from large scale in-situ tests of three severely ASR deteriorated bridges. The influence of ASR cracking on the mechanical properties of concrete and the prestress effect on the reinforcement due to ASR expansion are discussed. Keywords: ASR, bridges, pre-stress, compressive strength and shear capacity 108

110 5ICAAR2016_085 IMAGE ANALYSIS OF ALKALI-AGGREGATE GEL IN CONCRETE PRISM TEST WITH ALKALI-WRAPPING Go Igarashi¹, Kazuo Yamada 2, Yanfan Xu 3, Hong Wong 3, Shinichi Hirono 4, Shoichi Ogawa 5 1 Tohoku University, Life Cycle Engineering Laboratoy, SENDAI, Japan 2 National Institute for Environmental Studies, Research Center for Material Cycles and Wastes Management, TSUKUBA, Japan 3 Imperial College, Department of Civil & Environmental Engineering, LONDON, United Kingdom 4 Taiheiyo Consultant, Analysis Technology Division, SAKURA, Japan 5 Taiheiyo Consultant, Sales & Marketing Department, TOKYO, Japan The results from concrete prism test with alkali wrapping (AW-CPT) show complex ASR expansion behaviour that is dependent on temperature and alkali content. In this study, concrete prisms were made with two types of aggregate i.e. rapid expansive andesite containing opal/cristobalite and chert containing chalcedony and cryptocrystalline quartz. ASR was accelerated by increasing the exposure temperature up to 60 ºC and alkali content to 5.5 kg/m 3. An image analysis method was developed to quantify the alkali-silica gel content by treating the samples with uranyl acetate and measuring the emitted fluorescence with a high sensitive camera. Procedures for sample preparation, treatment and imaging were optimized. The results showed that alkali-silica gel inside reactive aggregates may exude out around the reacting aggregate and onto the surface of polished section. A general correlation was observed between the measured ASR gel amount and expansion. KEYWORDS: fluorescent, uranyl acetate, dyeing period, curing period, exposure temperature 109

111 5ICAAR2016_086 AGING MANAGEMENT OF NUCLEAR POWER PLANTS IN JAPAN WITH RESPECT TO THE ALKALI SILICA REACTION Kazuo Yamada 1, Ippei Maruyama 2, Shoichi Ogawa 3, Yuichiro Kawabata 4, 5, Toyoaki Miyagawa 6, Takamasa Ochiai 7 1 National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Tsukuba, JAPAN 2 Nagoya University, Graduate School of Environmental Studies, Nagoya, JAPAN 3 Taiheiyo Consultant, Sales & Marketing Division, Tokyo, JAPAN 4 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la- Vallée, FRANCE 5 Port and Airport Research Institute, Structural Engineering Division, Yokosuka, JAPAN 6 Kyoto University, Center for the Promotion of Interdisciplinary Education and Research, Kyoto, JAPAN 7 Chief Project Manager of Nuclear Safety Research Division, Mitsubishi Research Institute, Inc., JAPAN Aging management of concrete structures in existing nuclear power plants with respect to the alkali silica reaction (ASR) is a challenge in Japan. The Nuclear Regulation Authority (NRA) has been organizing a project on advanced integrity evaluation technology for aging management of structures. In this paper, the activities of a working group studying the ASR are introduced. ASR management does not only mean identification or diagnosis of ASR but also includes performance evaluation of structures in order to judge whether the structure can maintain its performance during a required period. The NRA has a pivotal role in evaluating applications provided by utility companies for aging management of nuclear power plants (NPP). However, in Japan, the available countermeasures for ASRs are intended for general civil structures and architectural buildings, and there is insufficient experience and data related to evaluation systems for NPPs, which require high-level safety and multifunctions, such as shielding performance, pipe and cable supporting performance, and seismic performance. In particular, regarding slow-reactive aggregates, which have been under focus recently, quantitative data are scarce and evaluation methods and countermeasures have not been established. Therefore, in the current project, before discussing aging management, the alkali reactivity of typical Japanese reactive aggregates are first evaluated using various Japanese and international test methods and a reasonable procedure for evaluating the alkali reactivity of aggregate or concrete mixtures is investigated. Next, methods for ASR diagnosis are verified. Simultaneously, concrete expansion estimation and performance evaluation within the scope of aging management are discussed, and target research topics are outlined for establishing an effective evaluation system for NPP concrete structures at risk of ASR-induced damage. Keywords: nuclear power, ageing management, alkali reactivity, performance test, future estimation 110

112 15ICAAR2016_107 EVALUATION OF THE CONCRETE PRISM AND THE ACCELERATED MORTAR BAR TESTS FOR ASSESSING THE POTENTIAL ALKALI-SILICA REACTIVITY OF RECYCLED CONCRETE AGGREGATES Sean Beauchemin *1, Benoit Fournier 1, Josée Duchesne 1 1 Dept. of Geology and Geological Engineering, Université Laval, Quebec, Quebec, CANADA The concrete prism test (CPT) and the accelerated mortar bar test (AMBT) are widely used tools for the assessment of alkali-silica reactivity of any given natural aggregates. This paper presents the evaluation of the above methods for evaluating the potential alkali-reactivity of recycled concrete aggregates (RCA). The testing was carried out on concrete prisms and mortar bars using respectively coarse RCA (CPT), as well as crushed RCA and crusher s fines (obtained from the primary crushing of the demolition concrete). The results showed that the behaviour in the CPT is very much related to the nature of the original virgin aggregates used in concrete manufacturing and the extent of ASR developed in the concrete prior to its demolition. In the case of the AMBT, the processing operations used to manufacture the fine size fractions required for mortar manufacturing has a critical impact on the proportion of residual mortar in the recycled concrete particles and, consequently, on the extent of mortar bar expansion. Consequently, a better correlation is obtained when CPT results are compared to that obtained when the AMBT is performed on crushed RCA. Keywords: Recycled concrete aggregate, alkali-reactivity, concrete prism test, accelerated mortar bar test, residual mortar; 111

113 5ICAAR2016_127 COMPREHENSIVE ASSESSMENT OF THE CAHORA BASSA DAM S CONCRETE SWELLING PROCESS António Lopes Batista 1, Ezequiel Fernandes Carvalho 2, Ilídio Marcos Tembe 2 1 Laboratório Nacional de Engenharia Civil (LNEC), Lisbon, PORTUGAL 2 Hidroeléctrica de Cahora Bassa (HCB), Songo, MOZAMBIQUE Cahora Bassa dam is a 171 m high arch dam, of the double curvature type, built in the 1970s on the Zambezi River, in Mozambique. The dam s concrete is affected by a moderate swelling process, due to alkali-aggregate reactions (AAR) of the alkali-silica (ASR) type, identified in the eighties of the last century, a few years after the construction (1970 to 1975). The owner, the Hidroeléctrica de Cahora Bassa (HCB), in the scope of the general activities of monitoring and safety control, has been increasing the monitoring system and additional testing, to allow a proper characterization of that pathology. The results of laboratorial accelerated expansion tests in samples extracted from the dam s body, of periodic analysis and the interpretation of the dam s structural behaviour, based on numerical models of the dam and on the monitoring results, and of regular visual inspections, completed the framework of engineering activities to catch the core knowledge about the swelling phenomenon and its main effects. The paper presents some relevant monitoring results and describes the main procedures related with the safety control activities, in order to allow a comprehensive phenomenon assessment and the correct timely decision making. Keywords: Cahora Bassa dam, alkali-silica reaction (ASR), monitoring data, swelling comprehensive assessment 112

114 5ICAAR2016_128 CHARACTERISTIC BEHAVIOUR OF THE PORTUGUESE LARGE CONCRETE DAMS BUILT WITH GRANITE AGGREGATES AND AFFECTED BY ASR António Lopes Batista 1, José Piteira Gomes 1 1 Laboratório Nacional de Engenharia Civil (LNEC), Lisbon, PORTUGAL In a universe of about sixty large concrete dams monitored in Portugal, there are 19 dams affected by swelling processes already identified. From these, there are 13, where coarse granite aggregates were used in the concrete composition, built between about 1940 and 1980, affected by alkali-silica reactions (ASR), which exhibit a behaviour characterized by very low expansion rates during the first 20 to 30 years, but showing since then increasing rates. Some dams in which this characteristic behaviour occurs are described in the paper, as well as the related structural effects in each one. The monitoring results of the 13 concrete dams, where granite aggregates were used, were obtained with specific devices. They show accumulated expansions of about 200x10-6 and current average free swelling rates of about 10x10-6 per year in most of them. However, there is one case in which the accumulated strain and the current swelling rate reach about 500x10-6 and 25x10-6 per year, respectively. Since the swelling magnitude values are moderate, no problems related with serviceability and safety are expected in the near future. However, the standard tests of accelerated expansion performed on samples taken from the body of some of these dams showed a much lower growth potential than the one recorded on site. For this reason monitoring of these dams and careful analysis of the results should continue. Keywords: Portuguese concrete dams, alkali-silica reaction (ASR), coarse granite aggregates, monitoring data, swelling estimation 113

115 5ICAAR2016_ YEAR MANAGEMENT OF 253 BRIDGES POTENTIALLY AFFECTED BY AAR Marc Brouxel 1*, Grégoire Segent 2, Yannick Jeanjean 3, Bruno Godart 4 1 CONCRETE SARL, allée des Gingkos, Bron, FRANCE 2 CONCRETE SARL, Campus de la Cessoie, 41 rue Simon Vollant, Lambersart, FRANCE 3 SANEF, Direction Construction et Patrimoine, BP50073, Senlis cedex, FRANCE 4 UNIVERSITE Paris-Est, IFSTTAR, Bd Newton, Champs-sur-Marne cedex 2, FRANCE The aim of this paper is to present the asset management methodology developed, adapted and followed by SANEF (French conceded highway operator) after discovering the first signs of AAR disorders on highway bridges in During the first period ( ) a general overview of the 253 bridges from A26 highway was realized: that allowed to classify the bridges into 5 groups (not concerned: 29 bridges, highly deteriorated: 24 bridges, deteriorated: 63 bridges, slightly deteriorated: 116 bridges, less affected: 21 bridges). In the second period ( ), a simplified monitoring was installed and a material diagnosis was performed on the most deteriorated bridges. These studies were also conducted, over the years, on the bridges showing new disorders. During the third period ( ) the simplified monitoring was continued on all the bridges, and the most deteriorated bridges were protected (implementation of a sealing coating on the walls and piers and waterproofing of the deck). Sensors were installed to detect any abnormal dimension variations. During this period, some verifications were conducted to validate the repair methodology (verification of the absence of disorders on the walls in contact with the soil, loading test to confirm the structural capacity of the most deteriorated deck, coating product testing). In 2006, a first assessment was conducted by the French authorities controlling the activities of the highway operators. It was decided to continue the simplified monitoring of the bridges. It was also decided to focus the monitoring of the coated bridges only with the sensors installed on metallic bars. The visual inspections were also maintained, especially to check the coatings degradation. In the last period ( ) some specific investigations were realized (verification of rebar along major cracks, loading test). A new assessment was performed in 2014 by the French authorities allowing to reduce the rate of the simplified monitoring to one measure per year. It was also decided to realize specific investigations and to replace the oldest coatings to avoid any water penetration into the concrete. Keywords: alkali-reaction, delayed ettringite, asset management, repair works, coatings 114

116 15ICAAR2016_ YEAR RESULTS OF AN IN-SITU MONITORING STUDY OF LARGE CONCRETE ELECTRICAL TOWER FOUNDATIONS AFFECTED BY ALKALI-SILICA REACTION (ASR) Benoît Durand 1, Benoît Fournier 2 1 Hydro-Québec Research Institute, QC, CANADA 2 Department of Geology and Geological Engineering, Université Laval, QC, CANADA In the late 1980 s, a survey revealed that several of the concrete foundations built between 1965 and 1973 and supporting large critical electrical towers were affected at different levels by ASR. In 1991, a specific monitoring program was started to evaluate the behavior of some 30 repaired and non-repaired foundations. Surface deformation measurements along with visual periodic inspection were done from 1992 to Results showed that none of the products and repair techniques completely prevented the expansion, even the reconstruction method because a slightly alkali-reactive limestone aggregate was used in the new concrete. The main conclusion is that most of the concrete foundations show relatively similar rates of surface expansion after 20 years of monitoring than the ones observed during the first 8 years of monitoring. It is important to point out that none of the detected damage to the concrete foundation is considered to affect the overall structural integrity of steel towers. Keywords: AAR, concrete foundations, long-term monitoring, repair methods 115

117 15ICAAR2016_196 COMBINATION OF NUMERICAL MODELLING AND LABORATORY TESTING TO ASSESS THE ALKALI-SILICA REACTION (ASR) AT RAPIDES-DES-ÎLES HYDROELECTRIC POWER PLANT, QUÉBEC, CANADA Benoît Durand¹, Mario Veilleux 2 1 Hydro-Québec Research Institute, QC, CANADA 2 Dams Expertise, Hydro-Québec Production, QC, CANADA The hydroelectric power plant Rapides-des-Îles is located about 500 kilometers northeast of Montréal, Québec, Canada. The concrete of this 238 m long and 34 m high power plant is affected by alkali-silica reaction since its construction, which began in 1966 and ended in At the beginning of the construction of RDI development, the laboratory testing had not demonstrated potential reactivity between aggregates and alkalies. The reaction and associated concrete swelling have caused functionality issues at the gates of the spillway, misalignments of the generating units that required several realignments over the years and induced some polygonal cracking in several places as well as structural cracks aligned parallel to main reinforcement. Consequently, various technical surveys have been done over time to diagnose and confirm the presence of an alkali-silica reaction associated with the coarse aggregate. Since the degree of swelling associated with ASR measured at monitoring devices did not seem to slow down, a numerical modelling program was initiated in 2014 to evaluate the behavior of the main dam and to reproduce its past and future behavior. After studying different models, the numerical model developed by Electricité de France (EDF) - Code_Aster - was selected. This numerical model requires the evaluation of several parameters characterizing the different phenomena: mechanics, creep, hydric and ASR effects. This assessment is made by conducting a series of laboratory tests from concrete cores extracted from the dam along with concrete cylinders made with the original aggregate to characterize the concrete from the beginning. This article presents the laboratory test program defined to determine the parameters specific to AAR in the model. Keywords: AAR modelling, history case, dam, Code_Aster, laboratory tests. 116

118 5ICAAR2016_198 SEMI-QUANTITATIVE CONDITION ASSESSMENT OF CONCRETE DISTRESS THROUGH THE DAMAGE RATING INDEX Leandro Sanchez 1*, Benoit Fournier 2, Thano Drimalas 3, Josée Bastien 2, Denis Mitchell 4, Martin Noel 1 1 University of Ottawa, Ottawa, ON, CANADA 3 University of Texas, Austin, TX, USA 2 Université Laval, Québec, QC, CANADA 4 McGill University, Montréal, QC, CANADA The Damage Rating Index (DRI), a microscopic and semi-quantitative petrographic tool, is a method which has increasingly been used in North America and Europe, since it may answer some interesting questions about the nature and current condition of damaged concrete. However DRI has mostly been performed on ASR-affected samples and there is currently very few data on the evaluation of other distress mechanisms, such as delayed ettringite formation (DEF), freezing and thawing cycles (FT), etc. This work presents the microscopic assessment of 35 MPa concrete mixtures affected by ASR, DEF and FT, with the aim of verifying the comprehensive diagnostic character of the DRI for assessing distress in concrete. The results show that the DRI number enables the global evaluation of concrete distress, disregarding the damage mechanism type. Moreover, the use of an extended DRI makes still easier the understanding of the development of different distress processes against the expansion levels of affected specimens. Keywords: alkali-aggregate reaction, crack detection, degradation, damage rating index, durability 117

119 15ICAAR2016_205 DESIGN FOR WIDENING OF EXISTING BRIDGE PIERS AFFECTED BY ALKALI-SILICA REACTION (ASR) Yoshinori Horioka¹, Hiroshi Kobayashi 1, Hiroki Sugiyama 1,Sei Taniguchi 1, Susumu Inoue 2 1 Hanshin Expressway Company Limited, Osaka, JAPAN 2 Osaka Institute of Technology, Osaka, JAPAN As a part of a project to add extension girders to an expressway bridge, it was planned to widen existing T-shaped concrete pier beams and install external tendons to support the new girders with an enhanced flexural capacity. However, numerous cracks were found in the surface of the beams after removal of protective coatings, suggesting a possibility of deterioration by alkali silica reaction (ASR). Detailed investigations demonstrated that the concrete was actually damaged by ASR. Since the beams were to be prestressed by the external tendons over the whole length, it was necessary to check the soundness of concrete inside the beams. Ultrasonic tomography was applied to evaluate the properties of the inner concrete. This paper reports the detailed investigations and strengthening designs for the ASR-affected piers. Keywords: widening, visual inspection, external tendon, ultrasonic tomography 118

120 5ICAAR2016_214 LABORATORY METHODOLOGY FOR EVALUATING THE EXPANSION PROCESS IN STRUCTURES AFFECTED BY AAR Marco Juliani 1, Francisco Andriolo 2, Daniela David 1, Tiago Juliani 1 1 IEME BRASIL Engenharia Consultiva, São Paulo, SP, BRAZIL 2 ANDRIOLO Engenharia, São Carlos, SP, BRAZIL This paper presents a suggestion of a new laboratory routine methodology for evaluating the expansive phenomenon of the concrete in structures affected by AAR. The experiments performed in laboratory were compared to measurements carried out by instrumentation in the field and also to the results of a numerical analysis. The conceptual basis of the proposed method considers the effects of expansion from exposure in different conditions of temperature and humidity, establishing a regression to the environmental conditions in which it operates. The specimens tested are prepared from drilled cores, extracted from the affected structure. The similarity of values obtained, even considering the randomness of the samples used, the measurement points in the structures and the complexity of the reactions, suggests deepening of evaluations, based on the new methodology proposed. Keywords: laboratorial methodology, alkali-aggregate reaction, instrumentation in the structures, expansion, time to reduce the expansions 119

121 5ICAAR2016_233 DIGITAL IMAGE ANALYSIS OF DETERIORATED CONCRETE TREATED WITH URANYL ACETATE FOR DETECTION OF ALKALI AGGREGATE REACTION Cecilia Olague 1, Gustavo Olague 2, José A. Pérez 3, Eddie Clemente 4, Gilberto Wenglas 5, José Castañeda 6 1, 3, 5, 6 Universidad Autónoma de Chihuahua, Facultad de Ingeniería, Chihuahua, Chih., MÉXICO 2, 4 Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Ciencias de la Computación, Ensenada, B. C., MÉXICO Despite decades of study of Alkali Aggregate Reaction (AAR), its understanding is complex and its potential prediction is difficult. The AAR detection is made by means of different field and laboratory tests, and once detected its effects are measured. A common AAR tests is the Rapid Identification of Alkali Silica Reaction Products, which causes that alkali ions contained in the gel AAR become visible as fluorescent and bright areas under ultraviolet illumination. However, these areas do not necessarily show the presence of AAR, as they may appear as a consequence of concrete carbonation or sodium content in the cement paste. This paper present a new method to detect reactive zones in deteriorated concrete samples treated with uranyl acetate using digital images in a computational model of visual attention. The results show the feasibility of identifying more quickly and accurately the presence of zones where AAR occurred in concrete infrastructure. Keywords: Deteriorated concrete, reactive zones, visual attention, digital images 120

122 15 th ICAAR 2016 BRAZIL THEME 06 CASES OF DETERIORATION

123 15ICAAR2016_019 EVALUATION OF THE DEGREE OF DAMAGE CAUSED BY ALKALI- SILICA REACTION IN A HIGHWAY PAVEMENT: A CASE STUDY Anthony Allard 1, Benoît Fournier 1, Josée Bastien 1, Benoît Bissonnette 1, Léandro Sanchez 2, Josée Duchesne 1 1 Université Laval, Québec, QC, CANADA 2 University of Ottawa, Ottawa, ON, CANADA The evaluation of the current condition and cause of deterioration is a key element for elaborating remedial actions in aging concrete structures. Several tests, such as the Stiffness Damage Test (SDT) and the Damage Rating Index (DRI), were developed over the years and optimized to propose a protocol for reliably evaluating the condition of concretes affected by alkali-silica reaction (ASR). Near Bécancour, QC, Canada, a highway concrete pavement never opened to traffic and affected by ASR presents an interesting case for the application of the proposed protocol for the evaluation of the damage caused by ASR. Four sections of highway, showing varying degrees of visual deterioration, were cored and multiple tests were carried out, such as the SDT, the DRI, the gas pressure tensile test, splitting-tensile strength and direct tension test. Statistical analyses of the test results were performed in order to verify whether the proposed protocol is applicable. Keywords: Alkali-Silica Reaction, Stiffness Damage Test, Damage Rating Index, pavement, damage 122

124 15ICAAR2016_042 DIAGNOSIS OF ALKALI-SILICA REACTION IN AIRPORT PAVEMENT IN JAPAN Naoya Kawamura 1, Yuichiro Kawabata 2,3, Tetsuya Katayama 4 1 Airport Facilities Division, Airport Department, National Institute for Land and Infrastructure Management, Yokosuka, JAPAN 2 Structural, Engineering Division, Port and Airport Research Institute, Yokosuka, JAPAN 3 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la- Vallée, FRANCE 4 Taiheiyo Consultant Co., Ltd., Sakura, JAPAN Petrographic examination and accelerated expansion tests were performed to clarify the causes of cracking due to alkali-silica reaction (ASR) in concrete pavement in a Japan airport. The deterioration was due to pessimum proportion effects caused by early-expansive ASR. ASR gel was observed in sand aggregates containing highly reactive minerals that exhibit pessimum proportion effects. Estimation of alkali contents in concrete confirmed the occurrence of ASR even when the total amount of alkali in the cement used was below 3.0 kg/m 3, which is the current regulated threshold for preventing ASR in Japan. Two types of complementary test methods were also performed; one was a reassessment of the structural performance of the affected pavement, and the other was an investigation of the relationship between the results of an expansion test and field behaviour. This study suggests that a falling weight deflectometer may be a promising tool for evaluating the performance of affected pavements, and that a modified expansion test to avoid alkali leaching can simulate slow expansion behaviours observed in the field. Keywords: airport pavement, polarizing microscope, alkali contents, earlyexpansive ASR, accelerated expansion test 123

125 15ICAAR2016_047 REVISITING AN HISTORIC CASE STUDY: MONITORING AND ASSESSMENT OF ASR IN A DECOMMISSIONED LOCK STRUCTURE Eric R. Giannini 1, Stephanie G. Wood 1, James H. Sanders 2, E. Rae Reed-Gore 3, Kyle L. Klaus 3, and Robert D. Moser 3 1 The University of Alabama, Tuscaloosa, AL, UNITED STATES OF AMERICA, 2 U.S. Army Corps of Engineers, Mobile, AL, UNITED STATES OF AMERICA 3 U.S. Army Engineer Research and Development Center, Vicksburg, MS, UNITED STATES OF AMERICA The Old Oliver Lock is a decommissioned lock structure on the Black Warrior River in Tuscaloosa, Alabama, USA. Constructed between 1937 and 1939, it was one of the first concrete structures in the eastern United States where ASR was identified as a cause of distress. A new lock went into service in 1992, but the old lock was not demolished and remains accessible for study. In 2015, a team of researchers began a new study of the old lock structure. The detailed records available from the construction of the lock and the subsequent investigation of ASR that followed make it an ideal field structure for applying modern monitoring and assessment protocols. The team selected four monoliths from the south wall of the lock with distinct variations in the degree of cracking for study. Core samples were also taken from each monolith under study and DEMEC targets for expansion monitoring were installed. This paper presents an overview of the study and selected results from petrography of the cores. Keywords: hydraulic structure, case study, mechanical properties, petrography, structural monitoring 124

126 15ICAAR2016_069 REMEDIATION STRATEGIES INTENDED FOR THE RECONSTRUCTION OF THE ASR-INDUCED MACTAQUAC DAM Edward G. Moffatt 1, Michael D.A. Thomas 1, Sean Hayman 2 Benoit Fournier 3, Jason Ideker 4, John Fletcher 5 1 University of New Brunswick, Department of Civil Engineering, Fredericton, NB, CANADA 2 Varcon Inc., Fredericton, NB, CANADA 3 University de Laval, Quebec City, QC, CANADA 4 Oregon State University, Covallis, OR, USA 5 NB Power, Mactaquac Generating Station, Keswick Ridge, NB, CANADA The Mactaquac Dam Generating Station is located on the Saint John River approximately 30-km outside of Fredericton, New Brunswick, Canada and was opened for service in the late 1960 s. Approximately ten years after power had begun being generated, significant deterioration and cracking was observed which was diagnosed as ASR in the mid 1980 s. In its current state, the dam has expanded approximately 6,000 microstrain (µε), which has resulted in expansion within and around the intake structure, powerhouse and spillways. Due to the ongoing deterioration, which has resulted in more than 600-mm to be removed by slot cutting, the dam is proposed to be rebuilt in Since a highly reactive greywacke aggregate is abundant within the region and may possibly be used in reconstruction, preventative measures including the use of supplementary cementing materials have been studied in order to mitigate the risk of ASR. A research study initiated in 2008 resulted in the production of five monolithic (3 x 3 x 3-m) concrete blocks produced at the foot of the generating station. Test specimens consist of a control containing a high-alkali Portland cement, three containing a low-calcium oxide fly ash with various replacement levels (30, 40 and 50%) and finally a block containing a reclaimed fly ash (50% replacement). Length-change and surface resistivity measurements have been conducted on a yearly basis to determine if or when expansion will initiate. This paper describes a research study, which was conducted in order to determine the appropriate remedial steps required to eliminate ASR using a locally available extremely reactive siliceous aggregate. The options being evaluated include the use of both high and low-cao fly ash as well as limiting the alkali content in the concrete. Methods for the evaluation of ASR include accelerated laboratory specimens of various sizes as well as large exposure blocks. Keywords: alkali silica reaction, pozzolans, fly ash, mitigation, field exposure 125

127 15ICAAR2016_105 ASSESMENT OF ALKALI-SILICA REACTION IN SOME CONCRETES FROM BRAZILIAN HYDROELECTRIC POWER PLANTS Nicole P. Hasparyk 1, Patrícia N. Silva 2, Danilo G. Batista 3, Heloísa H. A. B. Silva 1, Helena Carasek 3, Alberto J. C. T. Cavalcanti 2 1 ELETROBRAS Furnas, Gerência de Pesquisa, Serviços e Inovação Tecnológica, Goiânia, GO, BRAZIL 2 Companhia Hidro Elétrica do São Francisco - CHESF, Recife, PE, BRAZIL 3 Universidade Federal de Goiás - UFG, Goiânia, GO, BRAZIL Considering that the alkali-aggregate reaction (AAR) had already been diagnosed in several Brazilian hydroelectric power plants, it is important to continue the studies in order to monitor concrete behavior over the years and also to assist in remedial measures when necessary and in future mathematical models. Previous studies conducted in concretes of some structures of those plants have contributed significantly to the analysis of the behavior of the AAR over the years, with their various field investigations and extraction campaigns. The analysis of the characteristics and properties of concrete in different areas through continuous monitoring is very important as source of data about quality and durability of concrete. Considering the above, this paper aims to present a current overview of specific practical investigations in some concretes of five Brazilian hydroelectric plants from Chesf and Furnas. These studies were performed within the Furnas ANEEL R&D Program, and involved from field inspections to tests and analyses at laboratory. Keywords: HPP, concrete, alkali-aggregate reaction, quality, durability. 126

128 15ICAAR2016_115 OCCURRENCE OF LATE-EXPANSIVE ASR IN A GRANITOID ROCK WITH MICROGRAPHIC TEXTURE, HOKURIKU REGION, JAPAN SATO Tomomi 1, HIRONO Shinichi 1, KUBO Yoshinori 2 1 Taiheiyo Consultant Co., Ltd., Sakura, JAPAN 2 Kanazawa University, Kanazawa, JAPAN This paper reports an example of concrete deterioration due to late-expansive alkali-silica reaction (ASR) in a 45-year old bridge over Lake Kuzuryu, Fukui Prefecture, Hokuriku region, Japan. Core samples taken from reinforced concrete slabs were investigated petrographically. ASR occurred in granitoid rock with a micrographic texture containing microcrystalline quartz. In Japan, the only occurrence of ASR in granitoid rock rather than from a deformed rock containing cryptocrystalline quartz is from a cataclasite. However, ASR in granitoid rock free of secondary deformation was identified in this study. The graphic texture is a regular intergrowth of quartz and feldspar characteristic of these rocks. As the specific surface area of the quartz in this granitoid rock is large, similar to micro- to cryptocrystalline quartz in other slow-reactive rock types, the micrographic texture containing this quartz is believed to be capable of producing late-expansive ASR in concrete. Keywords: alkali-silica reaction, petrographic examination, graphic texture, granitoid rock, microcrystalline quartz. 127

129 15ICAAR2016_116 OLDEST EXAMPLE OF ALKALI-SILICA REACTION IN JAPAN TOKYO BAY SEA FORTS NO. 2 AND NO. 3, CONSTRUCTED YEARS AGO Yoko Ando¹, Tetsuya Katayama 1*, Shinichi Hirono 1*, Tomomi Sato 1*, Takatoshi Noguchi 2* 1 Taiheiyo Consultant Co.Ltd. Sakura, JAPAN 2 Tokyo Bay Waterway Office, Kanto Regional Development Bureau, MLIT, Yokosuka, JAPAN Concrete samples from Tokyo Bay sea forts, constructed over 100 years ago underwent late-expansive ASR of crypto- to microcrystalline quartz in the sedimentary gravel used (sandstone, chert and tuff). The minimum alkali content of the cement estimated by EDS analysis of unhydrated cement particles (alite, belite, aluminate and ferrite) in the hardened concretes, ignoring water-soluble alkali from alkali sulfates, ranged Na 2 Oeq %, which was sufficient to promote ASR. Reaction products of ASR had textures in common with those of modern ASRaffected concretes. Alkali-rich rosette-shaped crystals were similar in composition to shlykovite and rhodesite, when water contents were ignored. Portland cement particles were very coarse-grained, retaining unhydrated clinker phases. This suggests that cement hydration and strength development of the concretes were very slow and that large air voids absorbed ASR gel, thus accommodating expansion pressure generated by the ASR gel within reacted aggregates. Keywords: Alkali-silica reaction, petrographic examination, minimum cement alkali, shaft kiln,rotary kiln 128

130 15ICAAR2016_121 DIAGNOSIS OF ASR IN AIRPORT PAVEMENTS IN JAPAN EARLY- EXPANSIVE SAND AGGREGATE MISSED BY CONVENTIONAL TEST Tetsuya Katayama 1, Yoshinori Sarai 2 and Hiroki Sawaguchi 2 1 Taiheiyo Consultant Co.,Ltd Ohsaku, Sakura, , JAPAN 2 Kawasaki Geological Engineering Co., Ltd. Tokyo, , JAPAN This paper provides ASR diagnosis in a series of concrete pavement of a Japanese airport, based on petrographic examination, accelerated concrete core expansion test, and estimation of alkali contents in concrete. The pavement was built at a region free from freezing and thawing ranging in age from 20 to 4 years ago according to JIS specification (cement alkali Na 2 Oeq <3.0kg/m 3 ), but showed D- cracking and map-cracking. Highly reactive opaline mudstone in the coarse sand produced pop-outs and gel-filled cracks. Alkali contents in concrete indicated that total alkalis of cement was lower than Na 2 Oeq 2.5kg/m 3 with total concrete alkali content over 3.2kg/m 3, due to supply of water-soluble alkali from aggregates. Older concretes with late-expansive chert coarse aggregate presented small expansion in the accelerated test due to dissolution into alkali solution. Combination of blast furnace slag sand and fine sand in younger concretes reduced water-soluble alkali (about 30%) with negligible external signs of ASR but a potential for expansion in the accelerated test. D-cracking seems to be an effect of ASR with possible association of thermal stress. Keywords: airport pavement, alkali-budgets, D-cracking, early-expansive aggregate, petrography 129

131 15ICAAR2016_123 ASR FOUND IN THAILAND AND TROPICAL REGIONS OF SOUTHEAST ASIA Shinichi Hirono 1, Yoko Ando 1, Tomomi Sato 1, Kazuo Yamada 2, Hiroyuki Kagimoto 3, Kazuyuki Torii 4 1 Taiheiyo Consultant Co., Ltd., Sakura, JAPAN 2 National Institute for Environmental Studies, Tsukuba, JAPAN 3 Electric Power Development Co., Ltd., Kitakyushu, JAPAN 4 Kanazawa University, Kanazawa, JAPAN A case of ASR in Thailand was analyzed. It resulted from microcrystalline quartz in granite mylonites as coarse aggregate. Although ettringite formation was accompanied in existing cracks, the mechanism of expansion was attributed to ASR judged from the texture of expansive phases in the concrete. Another important reactive mineral was identified. Fine aggregate consisted of sand-sized granite which was free of microcrystalline quartz from secondary deformation such as mylonitization. Some micas in the granite have altered into allophane and/or opal, which could be products of weathering in hot and humid climates. Similar cases were also identified in neighboring countries, where granite that has altered to bare opal was used as crushed stone. This caused numerous pop-outs on the concrete surface. These opals are common to all tropical regions, including Southeast Asia, and various weathered rocks in tropical regions could contain potentially ASR reactive aggregates. Keywords: alkali-silica reaction, opal, petrographic examination, weathering, granite mylonite 130

132 15ICAAR2016_215 DIAGNOSIS OF ALKALI SILICA REACTION Viggo Jensen Norwegian Concrete and Aggregate Laboratory LTD, Sorgenfrivein 11, 7031 Trondheim, NORWAY The paper presents the authors many years experiences diagnosing Alkali Silica Reaction (ASR) in concrete structures. Correct diagnosis of ASR from field investigation to laboratory testing is mandatory for correct diagnosis. Very important is the investigators qualification and experiences on ASR and use of correct test methods. Micro structural analyses on fluorescence impregnated polished slabs and thin sections is probably the laboratory method, which gives most correct information on ASR and degree of damages. SEM/EDX gives additional information on reaction products and elemental distribution. The paper gives information on signs of ASR in concrete structures and by laboratory methods, important for correct diagnosis. For assessing the degree of damage it is recommended to do quantification of cracks in the concretes, e.g. by the Norwegian method described in the paper. Thin section analyses of a feldspar rock (rhomb porphyry) from Norway and a sericite rock from Thailand, are shown to be alkali reactive and presented in the paper. These rock types are not formerly reported to be potentially alkali reactive in international literature. Keywords: Concrete, Alkali Silica Reaction (ASR), Field-and Laboratory Testing, Microscopy, SEM/ EDX 131

133 15 th ICAAR 2016 BRAZIL THEME 07 STRUCTURAL EFFECTS OF AAR

134 15ICAAR2016_020 PERFORMANCE EVALUATION OF THICK CONCRETE SLABS AFFECTED BY ALKALI-SILICA REACTION (ASR) PART II : STRUCTURAL ASPECTS Sébastien Bilodeau 1, Anthony Allard 1, Josée Bastien 1, François Pissot 1, Benoît Fournier 1, Denis Mitchell 2, Benoît Bissonnette 1 1 University Laval, Québec, QC, CANADA 2 McGill University, Québec, QC, CANADA During the 1950 s s, it was assumed that concrete could provide adequate strength to ensure good structural behaviour of reinforced concrete slabs under shear stresses. However, recent introduction of certain mechanisms, such as scale factors, has raised new concerns about the structural capacity, especially for aging concrete slabs affected by ASR. In order to evaluate those concerns, a study was carried out to determine the residual shear capacity of thick concrete slabs sections without stirrups, affected by ASR as a function of its development. Eight concrete specimens, 610 x 750 x 4500 mm in size, were manufactured and subjected to conditions enabling ASR development. The thick slabs were tested up to failure at selected ASR expansion levels (0.07, 0.15 and 0.25%). Preliminary results suggest similar shear behaviour of non-reactive and reactive concrete slabs. Keywords: Alkali-Silica reaction, Thick concrete slabs, Shear strength, Size effect, Chemical prestress 133

135 15ICAAR2016_021 PERFORMANCE EVALUATION OF THICK CONCRETE SLABS AFFECTED BY ALKALI-SILICA REACTION (ASR) : PART 1 : MATERIAL ASPECTS Anthony Allard 1, Sébastien Bilodeau 1, François Pissot 1, Benoît Fournier 1, Josée Bastien 1, Benoît Bissonnette 1 1 Université Laval, Québec, QC, CANADA Concerns have been raised about the structural capacity of aging concrete slabs affected by ASR which reduces the mechanical properties of concrete, influencing the shear resistance mechanisms. As such, a study was carried out to determine the residual shear capacity of thick concrete slabs without stirrup with the progress of ASR. Two sets of three reactive and one non-reactive concrete specimens were fabricated and subjected to conditions conducive to the development of ASR. At selected expansion levels, one concrete specimen from each set was used to characterize the damage occurring within the specimens as it might affect the shear resistance mechanisms. The reduction in rigidity, compressive and tensile strength were evaluated and coupled with the Stiffness Damage Test and Damage Rating Index to fully evaluate the damage. The results suggest that a strong deterioration gradient is present within the specimens, influenced by the restraining effect of the bottom steel reinforcement. Keywords: Thick slabs, Deterioration gradient, Damage Rating Index, Stiffness Damage Test. 134

136 15ICAAR2016_023 STRUCTURAL IMPLICATIONS OF INTERNAL SWELLING REACTIONS IN CONCRETE: A REVIEW Martin Noël 1, Leandro Sanchez 1,Renaud-Pierre Martin 2, Benoît Fournier 3, Josée Bastien 3, Denis Mitchell 4 1 University of Ottawa, Ottawa, ON, CANADA 2 Institut français des sciences et technologies des transports, de l aménagement et des réseaux, Paris, FRANCE 3 Université Laval, Laval, QC, CANADA 3 McGill University, Montréal, QC, CANADA While the chemical and physical processes associated with alkali-aggregate reaction and delayed ettringite formation, otherwise known as internal swelling reaction mechanisms, have now been the subject of considerable research spanning several decades, the actual implications for affected structures are still open to debate. This may be partially attributed to the fact that parameters affecting structural response such as confinement effects, boundary conditions, anisotropy and loading conditions vary greatly among various structures. It is also worth noting, however, that the correlation between data obtained from material-level analyses and the in-situ performance of large-scale structures is still not well understood even at a fundamental level. This paper aims to synthesize our current knowledge of the structural implications of internal swelling mechanisms in concrete structures, in order to highlight major knowledge gaps and contribute towards a critical discussion of the importance of pursuing multi-scale testing regimes for the assessment of aging infrastructure. Keywords: Alkali-aggregate reaction; delayed ettringite formation; structural implications; aging infrastructure; concrete structures. 135

137 15ICAAR2016_028 STUDY OF BOND BETWEEN EPOXY, STEEL REINFORCING BARS AND CONCRETE AFFECTED BY ALKALI-SILICA REACTION Félix-Antoine Villemure 1, Mathieu Fiset 1, Josée Bastien 1, Denis Mitchell 2, Benoît Fournier 1, Benoît Bissonnette 1 1 Université Laval, Quebec City, QC, CANADA 2 McGill University, Montreal, QC, CANADA Installation of drilled-in epoxy bonded reinforcing bars is generally an effective strengthening method for deficient concrete structures. However, this method of rehabilitation has largely been studied and tested on sound concrete elements, i.e. without any pathological damage, which raises the question of bond capabilities in existing damaged elements. This investigation studies the influence of alkali-silica reaction (ASR) on the capacity of epoxy bonded anchors. ASR, which is very common in eastern Canada, results from the chemical reaction between the alkali hydroxides in the concrete s pore solution and some siliceous mineral phases in the aggregates. Pull-out tests on epoxy bonded anchors having embedded lengths of four times the bar diameter (Ø = 16 mm) have demonstrated a drop in bond strength when concrete is affected by ASR. In addition, the study revealed that the progression of concrete expansion due to ASR, leads to a confinement of the epoxy bonded anchor and increases the bond strength. These conclusions are therefore considered for the development of a model for the design of epoxy bonded anchors in existing concrete infrastructure affected by ASR. Keywords: post-installed bonded anchors, pullout test, alkali-silica reaction (ASR) 136

138 15ICAAR2016_041 SHEAR CAPACITY OF ASR DAMAGED STRUCTURES IN-DEPTH ANALYSIS OF SOME IN-SITU SHEAR TESTS ON BRIDGE SLABS Søren G. Hansen 1, Ricardo A. Barbosa 2, Linh C. Hoang 2, Kurt K. Hansen 2 1 Dept. of Technology and Innovation, Faculty of Engineering, University of Southern Denmark, DENMARK 2 Dept. of Civil Engineering, Technical University of Denmark, DENMARK This paper deals with the influence of alkali-silica reaction (ASR) on the shear capacity for concrete slabs without shear reinforcement. An experimental full-scale in-situ program consisting of four slabs from a bridge (Vosnæsvej) has been carried out and the results have been published in ref. [1] with the principal author of this paper as co-author. After the experiments, a detailed measurement of the test specimens was conducted. Based on these measurements a thorough analysis of the experimental results was carried out and evaluated by a plastic model for shear capacity, Crack Sliding Model (CSM) and Eurocode 2 (EN ). The analysis shows that three experiments were highly affected by the preparation of the experimental setup. Only one experiment contained useful information about the shear capacity. The analysis of this experiment shows that the shear capacity is not reduced as much as the measured concrete compressive strength indicates. Furthermore, the analysis shows that the ASR-induced prestress may be the reason for this phenomenon. Keywords: Alkali Silica Reaction, Shear Capacity, Full Scale testing, Crack Sliding Model, Failure Analysis 137

139 15ICAAR2016_126 EXPANSION SLOT CUTTING TO COUNTERACT ALKALI AGREGGATE REACTION AT PEDRA DAM Alberto Jorge C. T. Cavalcanti 1, Patrícia Neves Silva 1, Thais Amorim A. da Silva 1, Rodrigo C. Soares 2 1 Chesf - Companhia Hidro Elétrica do São Francisco, Recife, PE, BRAZIL 2 Betonpoxi Engenharia, Recife, PE, BRAZIL The Pedra Dam, located in River de Contas, Bahia state in Brazil, was built between 1964 and In 1991 the presence of alkali-aggregate reaction (AAR) in concrete structures was detected by means of petrographic and electron microscopic analysis. The concrete expansion caused an internal tension on the end piers of the spillway transmitted by the adjoining blocks; this resulted in operating problems of the left end gate. In order to reduce the effects of the concrete expansion, four expansion slots were cut with diamond coated steel wires. A monitoring system consisting of 24 joint meters was installed at eight joints between the concrete blocks, including the four expansion slots and the four slots next to them. The displacements measured during the cutting operations showed different behaviors at the left and the right abutments. Keywords: Alkali-aggregate reaction, concrete dam, slot cutting, waterproofing 138

140 15ICAAR2016_142 ROLE OF PRE-CRACK FORMATION AND ALKALI SILICA REACTION ON CONCRETE Salhin Alaud *, Gideon P.A.G. van Zijl Department of Civil Engineering, Stellenbosch, SOUTH AFRICA An experimental study was designed to investigate the effect of mechanical cracks in concrete on ASR expansion. Concrete cubes were made from a reactive aggregate of Greywacke stone and ground granulated corex slag (GGCS) was added to half of the specimens. Half of the specimens were submerged in 1N NaOH solution at 80 C in accordance with ASTM C 1260, and the other half of the specimens were submerged in hot water at the same temperature. A wedge splitting test on the specimens was set to achieve a certain crack width after being subjected to accelerated ASR exposure and hot water. The cracked specimens were subsequently returned to their exposure conditions, and the crack widths were measured 2, 7, 14 and 28 days after they were pre-cracked, at the same positions. Test results indicated that the mechanical crack widths reduce due to ASR and thermal expansion with values that differ according to the initial crack widths and the binder composition. KEYWORDS: Crack formation, crack width, wedge splitting, alkali-silica reaction, combined action. 139

141 15ICAAR2016_159 COMPUTATIONAL STUDY ON STRUCTURAL PERFORMANCE OF ASR DAMAGED RC MEMBERS Naoshi Ueda 1, Hiroki Tsutsumi 1 1 Kansai University, Suita, Osaka, JAPAN In this study, computational investigation of structural performance of ASR damaged RC beams was conducted by finite element analysis. RC beams failed in various modes were analysed by means of integrated analytical method in which ASR expansion analysis and loading analysis were combined. In the analytical method, influences of ASR were taken into consideration as initial strains, initial stresses, initial cracks and deterioration of material properties. And the structural performances damaged by ASR were discussed by focusing on initial flexural stiffness, load carrying capacity and failure mode. As a result, it was confirmed that influences of ASR on the structural performance were different depending on the failure mode of sound beam since the failure mechanisms were different. The importance of the accurate estimation of deterioration and the consideration of failure mechanisms was mentioned. Keywords: structural performance, ASR expansion analysis, loading analysis, deterioration of material properties, chemical prestress 140

142 15ICAAR2016_173 EXPERIMENTAL AND ANALYTICAL STUDIES ON FLEXURAL BEHAVIOR OF POST-TENSIONED CONCRETE BEAM SPECIMEN DETERIORATED BY ALKALI-SILICA REACTION (ASR) Yukio Hiroi 1, Takashi Yamamoto 2, Yoshihiko Toda 3, Hideki Manabe 4, Toyo Miyagawa 5 1 Engineering Department, PC Division, IHI Construction Service Co., Ltd., Osaka, JAPAN 2 Department of Civil & Earth Resources Engineering, Kyoto University, Kyoto, JAPAN 3 Research Institute of System Technology, JIP Techno Science Corporation, Osaka, JAPAN 4 CORE Institute of Technology Corporation, Osaka, JAPAN 5 Infra-System Management Research Unit, Kyoto University, Kyoto, JAPAN It is critically important to properly and quantitatively evaluate mechanical performance of ASR-affected structures. However, there are no established methods for proper estimation of load carrying performance of ASR-affected structures because it is extremely difficult to determine the degree of three-dimensional deterioration by ASR. In this study real-scale large prestressed concrete (PC) beam specimens were exposed to 7.5 years of ASR deterioration for long-term measurement and subjected to flexural loading test. Core samples were taken from the specimens after the loading test for mechanical property tests on ASR-affected concrete. The authors carried out nonlinear FE analysis using the measured mechanical property values in an attempt to reproduce the loading test. This report discusses the mechanical property values of the concrete core samples, analysis techniques and a comparison between the analysis and the experiment. Keywords: post-tensioned prestressed concrete beam, static loading test, analytical method, flexural behavior, mechanical properties of drilled cores 141

143 15ICAAR2016_180 IMPACT OF MULTI-AXIAL STRESSES ON ASR EXPANSION Pierre Morenon¹,², Stéphane Multon 2, Alain Sellier 2, Etienne Grimal 1, François Hamon 3, Eric Bourdarot 1 1 Electricité de France, Centre d'ingénierie Hydraulique, EDF-CIH Technolac, Le Bourget du Lac Cedex, FRANCE 2 Université de Toulouse, UPS, INSA, LMDC (Laboratoire Matériaux et Durabilité des constructions), 135, avenue de Rangueil, F Toulouse Cedex 04, FRANCE 3 Electricité de France, Direction Etude et Recherche, EDF-DER, 1 avenue du Général de Gaulle, Clamart Cedex, FRANCE Among large civil engineering structures, some concrete dams are submitted to structural effects of Alkali-Silica Reaction (ASR). This is mainly due to the concrete composition and climatic conditions such as water supply. Thus, Electricité de France (EDF), the most important dam owner in France, has supported the ASR modelling development, in collaboration with the LMDC Toulouse for the last decades in order to ensure dams safety and optimize maintenance. In this work, the aim is to show how restraints can modify ASR expansions. The behaviour of concrete submitted to ASR under multi-axial loading is modelled in the poro-mechanical framework. It contains a creep model which allows a realistic interaction between ASR and structural behaviour to be considered. Furthermore, the mechanical part considers anisotropic damage of affected concrete and includes cracks reclosure. The model is also able to dissociate expansion micro-cracks and structural macro-cracks. An analysis of literature experiments is performed by using a model to simulate swelling cylinders under restraint. In these tests, specimens are loaded in uniaxial compression and the radial displacement is restrained by steel rings surrounding concrete cylinders. A global calibration is realised in order to validate the model with all restraints and loads. After the modelling fitting and validation, parametric study is performed in order to assess uni-axial behaviour of affected concrete in various loading conditions. Maximal stresses and damages are thus analysed. Finally, useful practical considerations for engineering are deduced. They can be used in order to help experts for the management of ASR damaged structures. Keywords: Alkali-Silica Reaction, concrete modelling, stresses effects, anisotropy 142

144 15ICAAR2016_181 SHEAR CAPACITY OF LARGE-SCALE RC BEAMS AFFECTED BY ASR Yasuhiro Mikata 1, Dean J. Deschenes 2, Oguzhan Bayrak 3 1 Osaka Institute of Technology, Osaka, JAPAN 2 Simpson Gumpertz & Heger Inc., USA 3 The University of Texas at Austin, USA Some reinforced concrete structures located in Houston, Texas, U.S.A., have deteriorated because of alkali silica reaction (ASR) and/or delayed ettringite formation (DEF). In these structures, cracking and reduced concrete strength can be confirmed by inspection. The long-term performance of the affected structures in terms of their strength and serviceability becomes questionable when diagonal cracking occurs. In such a situation, it is important to clarify the time-dependent relationship between ASR deterioration and the structural performance of reinforced concrete structures affected by ASR. In this study, the shear capacity, the relationship between the applied shear force and the deflection, and the shear crack conditions in ASR-affected specimens were evaluated experimentally and by using the finite element method. This paper compares the numerical and experimental results. Keywords: Large-scale model, Shear capacity, Chemical prestress, ASR expansion analysis, RC beams 143

145 15ICAAR2016_182 LONG-TERM DETERIORATION OF QUASI-ACTUAL SCALE PRESTRESSED CONCRETE BEAM DUE TO ALKALI-SILICA REACTION Takanobu Yokoyama¹, Toyo Miyagawa 2, Yukio Hiroi 3, Takashi Yamamoto 4, Hideki Manabe 5, Takashi Ookubo 6 1 Technology and Construction Section, Nippon PS Co., Ltd., Osaka, JAPAN 2 Infra-System Management Research Unit, Kyoto University, Kyoto, JAPAN 3 Engineering Department, PC Division, IHI Construction Service Co., Ltd., Osaka, JAPAN 4 Department of Civil & Earth Resources Engineering, Kyoto University, Kyoto, JAPAN 5 CORE Institute of Technology Corporation, Osaka, JAPAN 6 Engineering Section, Business Promotion Dapartment, Kawada Construction Co., Ltd., Osaka, JAPAN Degree of deterioration by alkali-silica reaction (ASR) varies between structures or between members or locations of a structure, depending on environmental or confinement conditions. Mechanical performance of concrete structures depends on the mechanical properties of concrete and reinforcing bars as well as those of the bond between them. In order to ensure safety of a structure damaged by ASR which affects mechanical properties of concrete, the degree of deterioration should be accurately determined for proper quantitative evaluation of the mechanical performance of the structure. This study consisted of long-term exposure and measurement followed by a loading test using unprecedentedly large-size prestressed concrete (PC) beam specimens simulating real PC structures affected by ASR. Control specimens were also prepared for comparison and subjected to the loading test. This paper reports results of the study and the visual observation of the cut sections of the specimens after the loading test. Keywords: post-tensioned prestressed concrete beam, quasi-actual scale, long-term exposure test, static loading test, visual observation of the cut section 144

146 15 th ICAAR 2016 BRAZIL THEME 08 MONITORING AND MODELING

147 15ICAAR2016_030 NUMERICAL STUDY ON RESTRAINMENT OF REINFORCED CONCRETE DUE TO AAR EXPANSION Mariana C. Posterlli 1, Rodolfo A. K. Sanches 1, Rodrigo R. Paccola 1, Rogério Carrazedo 1 1 USP, University of São Paulo at São Carlos School of Engineering, São Carlos, SP, BRAZIL Alkali aggregate reaction leads to formation of a hygroscopic expansive gel, which may cause volumetric expansion of the concrete. In presence of compressive stresses, expansion is decreased in the compression direction; however, if compression is not equally applied over the three directions, the restrained expansion is transferred to a less compressed direction. In this sense, rebars reduce AAR strain in its direction, but barely affect the others. This pathology may considerably reduce the life span of the structure, however, modelling of an AAR-damaged structure should forecast displacements and strains development, thus allowing maintenance and improving structural safety. In this work, we perform a numerical study on the effect of passive stresses induced by AAR strains on the degradation of reinforced structures. Keywords: reinforcement; reinforced concrete; stress effect; numerical modelling. 146

148 15ICAAR2016_032 INFLUENCE OF CREEP AND STRESS STATES ON ALKALI-SILICA REACTION INDUCED-EXPANSION OF CONCRETE UNDER RESTRAINT Yuichiro Kawabata 1, 2, Jean-François Seignol 1, Renaud-Pierre Martin 1, François Toutlemonde 1 1 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la- Vallée, FRANCE 2 Port and Airport Research Institute, Structural Engineering Division, Yokosuka, JAPAN Creep and applied stress states or restraints have a significant influence on deformation of reinforced concrete structures affected by alkali-silica reaction (ASR). This influence may also be important when a structure subjected to ASR is submitted for retrofitting/mitigation purposes to additional compression provided by jacketing or pre-stressing. It still remains controversial, however, how the combination of creep and stress states or restraints affect the expansion behaviour of concrete induced by ASR. This paper describes the model proposed to account for the influence of creep and stress states on the expansion of concrete induced by ASR on the basis of chemo-visco-elasticity. Experimental results of the literature were compared to calculated ones which can be obtained by the proposed macroscopic model. The results emphasized a necessity to take creep and damage into account for numerical re-assessment of ASR-affected concrete. Keywords: alkali-silica reaction, creep, model anisotropy, damage 147

149 15ICAAR2016_033 MODELLING OF EVOLUTION OF TRANSFER PROPERTIES DUE TO EXPANSION OF CONCRETE INDUCED BY INTERNAL SWELLING REACTION Yuichiro Kawabata 1, 2, Renaud-Pierre Martin 1, Jean-François Seignol 1, François Toutlemonde 1 1 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la- Vallée, FRANCE 2 Port and Airport Research Institute, Structural Engineering Division, Yokosuka, JAPAN This paper presents a coupling model between expansion due to internal swelling reactions (ISR) and evolution of transfer properties. The coupling model was devised based on previous experiments and then trial calculations were performed. According to the trial calculations with simplified conditions, the simulated results with coupling showed quite different behaviour from the ones without coupling. The results emphasized the importance of taking into account the evolution of transfer properties due to ISR expansion to obtain more reliable prediction of concrete structures affected. 148

150 15ICAAR2016_034 CORRELATION BETWEEN LABORATORY EXPANSION AND FIELD EXPANSION OF CONCRETE: PREDICTION BASED ON MODIFIED CONCRETE EXPANSION TEST Yuichiro Kawabata 1, 2, Kazuo Yamada 3, Shoichi Ogawa 4, Renaud-Pierre Martin 1, Yasutaka Sagawa 5, Jean-François Seignol 1, François Toutlemonde 1 1 Université Paris-Est, IFSTTAR, Materials and Structures Department, Marne-la- Vallée, FRANCE 2 Port and Airport Research Institute, Structural Engineering Division, Yokosuka, JAPAN 3 National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Tsukuba, JAPAN 4 Taiheiyo Consultant, Sales & Marketing Division, Tokyo, JAPAN 5 Kyushu University, Department of Civil and Structural Engineering, Fukuoka, JAPAN This paper presents a correlation between laboratory expansion tests and field expansion of concrete and a prediction model of ASR expansion at ambient environments. Modified concrete expansion tests and numerical simulation using some predictive models were integrated. In the concrete prism test, the method consisting in wrapping concrete specimens with clothes containing alkali solution was applied in order to avoid alkali leaching and drying (AW-CPT). The parameters in the models for expansion and temperature dependency were calibrated with AW- CPT and implemented in the predictive calculation. The environmental actions such as temperature and precipitation were modelled on the basis of meteorological information of exposure sites. The results with some simplified assumptions showed that the calculated expansion using AW-CPT exhibited satisfactory agreement with measured expansion of field-exposed concrete. It is also clear that the results of field exposure tests are strongly influenced by meteorological conditions. From these results, the methodology of the prediction and correlation between laboratory tests and field performance of concrete are discussed. Keywords: prediction, concrete prism test, alkali-wrapping, meteorological condition, modelling 149

151 15ICAAR2016_043 A MICROMECHANICAL MODEL OF ASR ANISOTROPY. APPLICATION TO AFFECTED COLUMNS. Laurent Charpin EDF R&D, Department of Mechanics and Materials of Components, Ecuelles, FRANCE Alkali Silica Reaction induces microscopic cracking which reduces the mechanical properties of affected concrete, and leads to macroscopic swelling. Under anisotropic loading, swelling and cracking are also anisotropic. This paper presents a model that aims at simulating the development of cracking at the microscopic scale. A micromechanical description of the concrete and an energy fracture criterion are used in this purpose. The model parameters have been identified on laboratory experiments of ASR under loading. The results are considered satisfactory up to loadings of 10 MPa. Finally, the model is used to assess the safety of 18 m high and 70 cm wide columns showing signs of chemical internal swelling, in a nuclear power plant operated by EDF in France. The model provides valuable information about the length change of the columns depending on the vertical load applied. The results helped taking important decisions about the rehabilitation procedures which are currently undertaken in EDF maintenance strategy. Keywords: ASR, anisotropy, energy criterion, poromechanics, field application 150

152 15ICAAR2016_061 STUDY OF THE STRUCTURAL BEHAVIOR OF PIRAPORA DAM AFFECTED BY ALKALI-AGGREGATE REACTION Rodrigo T. Santos 1, Gustavo A. Tristão 1, Lilian Q.G. Baima 1, Rafael E. Bizarro 1, Marcela B.S. Sollero 1 1 CONCREMAT Engenharia e Tecnologia S.A., São Paulo, SP, BRAZIL The Pirapora Dam, built in 1956, is a gravity dam consisting of pillars (counterfort) and a wide base wall, whose stability is mainly ensured by its own weight. In the 1990s, pathological manifestations were recognized in the dam concrete structure, due to Alkali-Aggregate Reaction (AAR). For proper comprehension of the situation presented by the dam, its structural behavior was simulated in a representative three-dimensional mathematical model, based on the Finite Element Method (FEM). In order to provide a reliable analysis of the actual dam structural behavior, a calibration of the model was performed using modal analysis, using the natural frequencies of the real structure obtained by dynamic structural tests, so that the natural frequencies of the theoretical model could match with the real natural frequencies (experimental). To elaborate the mathematical model the geometry of the structure and materials properties were considered, obtained through laboratory testing of extracted concrete samples of the structure, as well the dynamic structural tests. The calibrated numerical model of the dam aims to monitor and validate the results of existing instrumentation, predict the structural response and the AAR effects in the coming years and provide the basis to simulate the mitigation measures of the AAR effects and complementation of the existing instrumentation in the dam. The results obtained with the structural modeling and the deteriorating state verified in inspections in the structure allowed the evaluation of the dam s behavior aiming to preserve the life cycle and safety of the structure. Keywords: alkali aggregate reaction (AAR), Finite Element Method (FEM), Structural Modeling, Structural Monitoring, Dynamic Structural Test 151

153 5ICAAR2016_072 DEVELOPMENT OF A PRELIMINARY GENERAL MODEL OF OCCURRENCE OF ALKALI SILICA AGGREGATE REACTION IN CONCRETE STRUCTURES Nydia Romero B 1, Juan. Lizarazo-Marriaga 1 1 Universidad Nacional de Colombia, Bogotá, COLOMBIA Main research conducted on the alkali - silica reaction (ASR) have been focused on the modelling of the chemical reaction kinetics, diffusion processes, potential expansion and its subsequent influence on the mechanical properties of concrete. It is emphasized that most of these models consider that the concrete has been already affected by the reaction and therefore they do not provide tools to determine the likelihood that the reaction occurs. Based on the above scenario, this paper presents the results of a research in which a preliminary model of occurrence of ASR was developed by using geographical information system (GIS) tools, establishing a map of susceptibility of occurrence for the area near Bogota (Colombia). In order to carry out this research, a review of the technical literature on environmental and geographical parameters such as relative humidity and temperature, location of potentially reactive aggregates and cements with high alkali content was conducted. Keywords: modelling, occurrence, GIS maps, alkali - silica reaction 152

154 15ICAAR2016_099 NUMERICAL MODEL APPLIED TO THE REASSESSMENT OF THE SERVICEABILITY AND SAFETY OF AAR-AFFECTED POWER-PLANT Jean-François Seignol 1, Liviu Boldea 2, Raphaël Leroy 3, Bruno Godart 1 1 Université Paris Est, IFSTTAR, Champs-sur-Marne, FRANCE 2 Independant Consultant, SWITZERLAND 3 ALPIQ, Lausanne, SWITZERLAND Veytaux power-plant is a hydraulic facility affected by AAR. The concrete deformations of the structure are transmitted to sensitive equipments connected to it with major consequences on the serviceability and safety., Predicting the amplitude and rate of future displacements is an essential condition to choose the manager s strategy: adaptation of the equipment, repair or strengthening of the structure... The main difficulty lies in the heterogeneous moisture distribution which induces complex expansion gradients and the complex interactions between chemically-induced swelling and mechanical resistance of less-affected parts of the structure. Hence, the prediction of the displacement transmitted to the equipments requires a complete chemo-mechanical model of the structure. A macroscopic model is used and takes into account various coupling with moisture, temperature and stress states in the concrete. Its fitting requires several data: material samples from the structure for laboratory tests, monitoring devices for measuring displacements, moisture and temperature... The resulting heterogeneous displacements in the concrete structure allow to re-assess the stress-state generated in the anchored equipment, especially in the 130-m long main distributor pipe. Keywords: FEM, hydroelectricity, structure, prediction, serviceability 153

155 15ICAAR2016_100 CHEMO-HYGRAL AND PORO-MECHANICAL MODELING FOR ASR AND STRUCTURAL PERFORMANCE ASSESSMENT OF RC BRIDGE DECKS Yuya Takahashi 1, Yasushi Tanaka 1, Koichi Maekawa 1 1 The University of Tokyo, Tokyo, JAPAN This study aims to assess the impacts of alkali silica reaction (ASR) on the fatigue lives of reinforced concrete slabs used in bridge decks. The authors have been developing a 3D multi-scale computational platform to trace the chemical and physical events in structural concrete. Anisotropy rooted in migration and expansion of ASR substances in both micro-pores and crack gaps is modelled based upon the scheme of poro-mechanics. The developed models are applied to the fatigue life assessment of RC bridge decks. Previous experimental works on moving-wheel-type loading for bridge decks is referred for experimental verification. It is confirmed that the models introduced in this study may bring about fair behavioural simulation. Furthermore, both experiments and analyses indicate that ASR does not always cause unfavourable structural performances of RC slabs under repeated traffic loads, but it might have led to some extension of fatigue life. The proposed model also promotes the study on so called disintegration of concrete composites owing to the cyclic pore-pressure provoked by the fatigue loading. Keywords: alkali silica reaction, poro-mechanics, fatigue life, bridge deck 154

156 15ICAAR2016_166 QUANTUM PARTICLE SWARM OPTIMIZATION APPLIED TO AUTOMATED CRACK PATTERN ASSESSMENT OF BACKSCATTERED ELECTRON IMAGE IN CEMENTITIOUS SYSTEMS Eduardo Vieira Queiroga 1, Lucídio dos Anjos Formiga Cabral¹, Andressa Porto Vieira², Marçal Rosa Flores Lima Filho², Kelly Cristiane Gomes², Sandro Marden Torres² 1 Centro de Informática - Universidade Federal da Paraíba - UFPB 2 Centro de Tecnologia - Universidade Federal da Paraíba UFPB Paraíba, PB, BRAZIL Alkali-Aggregate Reaction (AAR) is a concrete pathology that is mostly acknowledged by its map cracking pattern look at macro-level. At micro-level, it is also well established that the formation of AAR gels can be responsible for the shaping of cracks within aggregates and pores. This paper presents an automatic crack detection in cementitious systems affected by mechanisms of cracking. The assessment was made via Scanning Electron Microscopy by using Back-scattered Electron Imaging (BEI) mode (Quanta 450 FEI). On this image mode, the grey level can be associated to particular features of hydration as well as pores and cracks in cementitious systems. The hydrated cement samples were sliced, ground and polished down to a quarter of microns prior to vacuum gold-sputtering process. The original grayscale scanned image of each BEI was analyzed by using morphological image processing techniques and threshold operations. A multilevel thresholding operation was performed by using the Quantum Particle Swarm Optimization (QPSO) approach to Otsu s criteria. The preliminary results point out to good performance and show a rough calculation for the area fraction phases, as well as the automatic crack measurements of the resulting binary image by graph algorithms. Keywords: Concrete, Backscattered Electron Image Analysis, Optimization, Crack Detection. 155

157 15ICAAR2016_238 MODELING THE ORTHOTROPIC EXPANSION INDUCED BY ALKALI- AGGREGATE REACTION: METHODOLOGICAL REVIEW AND PRACTICAL APPLICATION Alfonso Pappalardo Jr. 1, Ruy Marcelo de Oliveira Pauletti 2, Thomas Garcia Carmona 3, Tiago Garcia Carmona 3, Antonio Carmona Filho 3 1 Escola de Engenharia da Universidade Presbiteriana Mackenzie, São Paulo, SP, BRAZIL 2 Escola Politécnica da Universidade de São Paulo, São Paulo, SP, BRAZIL 3 Carmona Soluções de Engenharia São Paulo, SP, BRAZIL Many concrete reinforced structures throughout the world are suffering from deterioration induced by Alkali-Aggregate Reaction (AAR), with direct impact on their durability and serviceability. AAR produces concrete expansion, generally leading to undesirable deformations throughout the structure. Several methodologies have been proposed for using collected field data to feedback predictive mathematical models, usually based on Finite Element Method (FEM) for the interpretation and prediction of the behavior of concrete exposed to AAR. In this paper, we briefly review the AAR phenomenon and some of the mathematical models used to simulate it, and propose a numerical approach to simulate the orthotropic swelling of concrete subjected to AAR, by means of conveniently adjusted orthotropic thermal expansion coefficients. The methodology, which takes into account the influence of the induced confining compressive stress state, the restraint due to steel reinforcement and the relative humidity of concrete, is then applied to model the AAR effects on the actual case of a pillar and the foundation block supporting the arches of a large steel roof structure. Keywords: AAR, Alkali-Aggregate reaction, mathematical model, orthotropic swelling, confinement stress, reinforcement restraint 156

158 15ICAAR2016_239 MODELLING OF ALKALI-AGGREGATE REACTION IN CONCRETE PILE CAPS STRUCTURES Marco Juliani 1, Lucas Juliani 1, Tiago Juliani 1, Daniela David 1, Liana Becocci 1 1 IEME BRASIL Engenharia Consultiva, São Paulo, SP, BRAZIL Many concrete reinforced structures throughout the world are suffering from deteriorations induced by alkali-aggregate reaction (AAR), which directly impacts on their durability and serviceability. The concrete expansion produced by AAR leads to cracks throughout the structure. In this direction, this paper presents a methodology for assessing the effects and use of back analysis methods for the interpretation of the behavior of concrete by means of a predictive mathematical model based on finite element method. This approach allows simulating orthotropic swelling of concrete subjected to AAR, including effects of the reinforcement presence, the 3D stress state and humidity. A real case study will be presented, showing a set composed by column, pile caps and piles of a building foundation structure that suffered the effect of AAR. Keywords: steel roof structure, mathematical model, orthotropic swelling, confinement stress, restrain due reinforcement. 157

159 15ICAAR2016_275 STRUCTURAL EFFECTS OF AAR ON THE JAGUARI HYDROPOWERPLANT WATER INTAKE Haroldo M. Bernardes¹, Rogério O. Rodrigues¹, Renato Bertolino Jr.¹ ¹ Faculdade de Engenharia de Ilha Solteira UNESP The Jaguari hydropowerplant (HPP) water intake is been affected by a swelling process, due to alkali-aggregate reaction (AAR) as proved by cores extracted for petrographic analysis. A system composed of rod extensometers, crack meters, triortogonal meters and an innovative optical displacements meter was been installed to monitor the behavior of the structure. It is a concrete tower-like structure 63 m tall with buttresses. Relative humidity is measured and thermometers allow knowing temperature inside and outside the structure. This paper describes a computational model of the water intake structure and compare its results with the ones obtained from the monitoring system. The aim is to estimate future strains and displacements taking into account concrete isotropic properties, environmental and confinement conditions, creep effect and damage. Keywords: Alkali Aggregate Reaction, Finite Element Method, Structural Monitoring 158

160 15 th ICAAR 2016 BRAZIL THEME 09 REPAIR AND REMEDIAL MEASURES

161 15ICAAR2016_017 Effect of CFRP Wrapping Time on Expansion Development and Load Capacity of Circular Concrete Columns affected by Alkali- Aggregate Reaction Thamer Kubat 1,2*, Riadh Al-Mahaidi 3 and Ahmad Shayan 4,5 1 PhD candidate, Department of Civil & Construction Engineering, Swinburne University of Technology, Melbourne, Australia 2 Lecturer, Duhok Polytechnic University, Duhok, Iraq 3 Professor of Structural Engineering, Department of Civil & Construction Engineering, Swinburne University of Technology, Melbourne, Australia 4 Chief Research Scientist, ARRB Group Ltd, Melbourne, Australia 5 Adjunct Professor, Department of Civil & Construction Engineering, Swinburne University of Technology, Australia Fibre reinforced polymers (FRPs) are one of several techniques used to rehabilitate affected concrete members by alkali-aggregate reaction (AAR). A number of circular concrete columns 200 mm in diameter and 500 mm in height were cast from reactive and normal concrete. During the AAR process, the columns affected by AAR were confined by carbon fibre reinforced polymer (CFRP) at the ages of 15, 30, 45, 60, 90 and 120 days after casting, which represent different levels of expansion. The expansion of concrete was monitored, before and after confinement, up to six months after casting. The results indicate the efficiency of using CFRP as a confinement material to limit the AAR expansion of the affected columns. The results also show that the enhancement of ultimate load capacity of the affected columns depends upon the time of CFRP wrapping as related that to expansion level. Keywords: carbon fibre reinforced polymer (CFRP), alkali aggregate reaction (AAR), confinement efficiency, radial expansion, load capacity. 160

162 15ICAAR2016_062 SPILLWAYS AFFECTED BY ALKALI-AGGREGATE REACTION : TWO CASE STUDIES FROM HYDRO-QUEBEC Nathalie Ishak 1, Stéphane Meunier 2, Fateh Boussaha 1, Claudia Correa 1 1 Hydro-Québec Production, Structural dam engineers, Montréal, Québec, CANADA 2 Hydro-Québec Équipement et services partagés, Head of mechanical engineering, Montréal, Québec, CANADA Canadian Standards began to warn as to the effects of the presence of Alkali- Aggregate Reaction (AAR) in conventional constructions no sooner than in the 1960 s. Soon thereafter, dam owners recommended test specifications for new constructions until such tests became mandatory requirements. By this time, Hydro- Quebec had already built more than half of its spillways and outlet works. Today, several constructions have reached their useful life expectancy despite being affected by AAR. Nevertheless, these structures can be safely operated notwithstanding their age and distress conditions. This article presents two case studies on innovative rehabilitations that extend the useful life of these constructions and ensure the reliability and operability of their mechanical systems. In both cases, the observed signs of deterioration were deformed and tilted spillway piers narrowing the gates sluices, fractures and deformation of mechanical equipment components eventually causing gates to be damaged, jammed and inoperable. The instrumental measurements validated the observed deficiencies and provided design guidance to complete the required modifications to the structures. At Rapide-des-Îles, adaptive gates were made-to-measure and installed in the secondary spillway whereas at La Tuque, the overhead hoist supporting structure was made adjustable. Keywords: Alkali-Aggregate Reaction, Adjustable spillway Overhead Structure, Adaptive spillway gate 161

163 15ICAAR2016_101 MAINTENANCE AND REPAIRS ON THE WATER INTAKE OF JAGUARI HYDROPOWERPLANT AFFECTED BY AAR. Edvaldo Fabio Carneiro¹; Julio Cesar Pinfari¹; Tatiana P. Araripe Cappi¹; Mauro H. L.Covre¹. ¹CESP Cia. Energética de São Paulo, São Paulo, SP, BRAZIL In 2001 alkali-aggregate reaction (AAR) was confirmed at Jaguari Hydropowerplant (HPP), that belongs to CESP-Companhia Energética de São Paulo, through petrographic analysis of specimens taken from the water intake, foundation block of a steel catwalk and concrete columns/beams that supports an overhead crane. Since the detection, instrumentation was installed; researches and repairs have been implemented aiming to assure the structural integrity and keeping a safe operability of the hydropower plant. This paper presents the procedures, methodologies and results obtained after cracks repairs caused by AAR on the water intake, on the foundation block and columns that support the steel catwalk. Keywords: Hydropowerplant, water intake, alkali-aggregate reaction, waterproofing 162

164 15ICAAR2016_104 COATINGS AND SEALERS FOR MITIGATION OF ALKALI-SILICA REACTION AND/OR DELAYED ETTRINGITE FORMATION Racheal D. Lute¹, Kevin J. Folliard 1, Thano Drimalas 1, Charles Karissa Rust 2 1 The University of Texas, Austin, TX, USA 2 University of North Texas, Denton, TX, USA The use of concrete sealers to mitigate alkali-silica reaction (ASR) and delayed ettringite formation (DEF) has become increasingly popular. The research presented here was aimed at evaluating coatings and sealers that are intended to lower the internal relative humidity of concrete and thus reduce the future potential for ASRand/or DEF-induced expansion and cracking. For this research various coatings were evaluated via outdoor exposure site testing, concrete prism testing, and relative humidity monitoring. Large exposure blocks were treated with various coatings at selected levels of expansion, and expansion measurements for each block were obtained frequently in order to determine the effectiveness of the coatings in terms of their ability to reduce expansion due to ASR and DEF. Parallel concrete prism testing was conducted to determine how well ASTM C1293 could predict the effectiveness of coatings, particularly silanes. Relative humidity measurements were also obtained to evaluate the ability of each sealer to reduce relative humidity in concrete. Results from these tests confirmed that some sealers can reduce ASR and/or DEF related expansion by reducing the internal relative humidity of concrete. Keywords: alkali-silica reaction (ASR); delayed ettringite formation (DEF); silane; mitigation; relative humidity 163

165 15ICAAR2016_112 MEASURING RELATIVE HUMIDITY IN CONCRETE PAVEMENTS AS A METHOD TO ASSESS ASR MITIGATION MEASURES Remington Reed 1, Richard Deschenes Jr. 1, W Micah Hale PhD 1 1 University of Arkansas, Fayetteville, Arkansas, USA Alkali-silica reaction (ASR) in concrete is partly facilitated by available moisture within the concrete. In order to better understand this facilitation and to develop processes for ASR mitigation methods, it is necessary to establish a means of monitoring internal relative humidity (RH) within the concrete. Current procedures for measuring RH are time consuming; requiring several hours of equilibration time and specific external conditions to yield accurate results. In order to better understand RH monitoring, laboratory tests were conducted using commercially available RH probes and different controlled environments. Probes were carefully monitored and calibrated in controlled environments, and laboratory tests on internal RH were conducted on concrete slabs in ambient conditions as well as concrete prisms in controlled environments. Preliminary results show that differing probes must be calibrated at different intervals and require different equilibrium times. Current internal RH test procedures are inefficient in terms of equilibration and measurement parameters. KEYWORDS: Alkali-silica reaction (ASR), relative humidity, pavements, mitigation 164

166 15ICAAR2016_113 MITIGATION OF ALKALI-SILICA REACTION IN CONCRETE PAVEMENTS BY SILANE TREATMENT Richard Deschenes Jr. 1, Matthew Waidner 1, W. Micah Hale PhD 1 1 University of Arkansas, Fayetteville, Arkansas, USA Alkali-silica reaction (ASR) in concrete pavements is difficult to mitigate and causes maintenance issues, which often require overlays or replacement. The only effective method for mitigating ASR in pavements is by limiting moisture within the concrete, which reduces ASR related expansion. For pavements placed on well drained base layers it may be possible to mitigate ASR through surface treatment. Silane provides a breathable barrier on the surface of the concrete, which blocks water, while allowing water vapor to escape. The silane penetrates into the surface of the concrete and chemically bonds to it, providing a long term treatment. The ongoing research project at the University of Arkansas will assess the efficacy of silanes applied to concrete pavements. The mitigation efforts will be assessed through expansion and relative humidity monitoring, in addition to quantitative deterioration tests. Preliminary results show that silane can slow the progression of ASR in pavements. KEYWORDS: Alkali-silica reaction (ASR), silane, concrete pavements, mitigation 165

167 15ICAAR2016_148 STUDY OF SILANE COMPOSITIONS TO MITIGATE ALKALI-SILICA REACTION Cristiane M. S. Rua 1, Nicole P. Hasparyk 2, Paulo J.M. Monteiro 3, Denise Dal Molin 4, Luiz Eiger 5 1 Departamento Nacional de Infraestrutura de Transportes DNIT, Brasília, DF, BRAZIL 2 ELETROBRAS Furnas, Gerência de Pesquisa, Serviços e Inovação Tecnológica, Goiânia, GO, BRAZIL 3 University of California at Berkeley. California. UNITED STATES 4 Universidade Federal do Rio Grande do Sul UFRGS, Porto Alegre, RS, BRAZIL 5 Consutor. Rio de Janeiro, RJ, BRAZIL There are well-established preventive measures to reduce the potential damage to a concrete structure when reactive aggregates are used. However, there are only few efficient measures to apply to a structure once the deleterious reaction has already been established. So as to extend the ASR repair strategies, the present study aimed to verify, in laboratory, the mitigating potential of silane compositions in residual expansion of affected mortars cast with reactive aggregates. The results indicated that silane-based treatments, mainly the one containing octyltriethoxysilane, are very promising. Water absorption measurements and microstructural characterization bywith scanning electron microscopy of the mortar bars treated with silanes were also included in the experimental program. Keywords: expansion; mitigation; alkali-silica reaction; silane; treatments. 166

168 15ICAAR2016_192 THE REINFORCEMENT OF AN ASR AFFECTED INTAKE TOWER USING POST-TENSIONED TENDONS Tetsuji Kubo 1, Toshiharu Shibata 1, Chikao Sannoh 1, Kazuyuki Torii 2 1 Hokuriku Electric Power Co. Ltd., JAPAN 2 Kanazawa University, JAPAN One intake tower in Japan s Hokuriku district with a height of 62.7m was constructed between 1977 and 1979 for power generation and agricultural use. 20 years after the construction, an inclination with concomitant expansion of the structure was found due to the clearance of 40mm between the top of the intake tower and the connecting bridge. As a result of the investigation of the concrete, it was revealed that deformation had occurred as a consequence of ASR expansion of the intake tower concrete, and the inclination (horizontal displacement) from the vertical line reached 90mm after 10 more years. Countermeasures were carefully considered by academic experts, and post-tensioned tendons were inserted into the intake tower concrete (vertically oriented) so that the power station can continue to operate safely in the future. This is thought to be the first challenge of its type anywhere in the world for which the deformation of a real structure caused by ASR expansion must be controlled. This paper presents the overview of the investigation and the method of the reinforcement including the effect of the countermeasure. Keywords: ASR, Reinforcement, Deformation 167

169 15 th ICAAR 2016 BRAZIL THEME 10 CONCRETE DISTRESSED DUE TO COUPLED AAR AND DEF MECHANISMS / DEF

170 15ICAAR2016_037 COEXISTENCE OF ASR AND DEF IN A PRECAST PRE-STRESSED CONCRETE ELEMENT IN CHINA Duyou LU 1, Xiaopeng KANG 1, Yinong LU 1, Pierre-Luc FECTEAU 2, Benoit FOURNIER 2, Zhongzi XU 1 1 Nanjing Tech University, Nanjing, CHINA 2 CRIB - Quebec, Université Laval, Department of Geology and Geological Engineering, Quebec CANADA : To diagnose the cause of cracking of some concrete elements after 4-years in service, concrete cores drilled from the cracked elements were examined by chemical analysis, x-ray fluorescence(xrf), x-ray diffraction(xrd), thermogravimetric analysis, petrographic optical microscope and scanning electron microscopy/energy dispersive spectrum(sem/eds). Results show that a fair amount of fine aggregate particles and some coarse aggregate particles show obvious signs of alkali silica reaction (ASR). Ettringite with various morphologies have developed widely in the interfacial transition zone(itz) between aggregate and paste. Coexistence of the alkali-silica gel and ettringite is also easily identified in the ITZ between aggregate and paste. In reference to the findings in various tests and literature results, the cracking of the high performance concrete elements is probably caused by the combination of alkali silica reaction and delayed ettringite formation (DEF). Keywords: high performance concrete; alkali silica reaction; delayed ettringite formation; cracks; concrete durability 169

171 15ICAAR2016_063 THE EFFECTS OF DELAYED ETTRINGITE FORMATION ON THE EXPANSION OF A MASSIVE BRIDGE PIER AND A PRECAST PRESTRESSED CONCRETE BEAM OF A BRIDGE Bruno Godart 1, Othman Omikrine-Metalssi 1, Badreddine Kchakech 1, Stephane Lavaud 1 1 Université Paris Est - IFSTTAR, Marne La Vallée, FRANCE This article shows that Delayed Ettringite Formation (DEF) may affect massive parts of concrete structures as well as precast structural members through the presentation of two examples: a massive pier column and a precast prestressed concrete beam. For each of them the article presents a brief description of the structure, detailed information on the distress mechanism and cracking involved, residual expansion results obtained on concrete cores extracted, the assessment through the use of FEM analysis, considering a new model implemented in CESAR- LCPC software, and the recommended actions for their management including monitoring. The results highlight that the exposure conditions and the temperature reached provided a significant effect on the displacements and stresses of the structures affected by DEF. Keywords: delayed ettringite formation, expansion, cracking, assessment, FEM analysis. 170

172 15ICAAR2016_087 EXPERIMENTAL STUDY OF THE INFLUENCE OF LATE HEAT TREATMENT ON THE RISK OF EXPANSION ASSOCIATED WITH DELAYED ETTRINGITE FORMATION Kchakech B. 1, Martin R.-P. 1, Omikrine-Metalssi O. 1, Renaud J.-C. 1, Baron L. 1, Toutlemonde F. 1 1 University Paris Est IFSTTAR- Materials and Structures Department, Boulevard Newton, Champs-Sur-Marne, Marne la Vallée Cedex 2 FRANCE A long enough exposure to high enough temperature is a necessary condition to develop Delayed Ettringite Formation (DEF). Thermal conditions leading to DEF development have generally been investigated for concrete at early age. In this paper, the results of experimental laboratory investigations that aim to quantify the effect of a late thermal treatment on DEF characteristics (namely magnitude and kinetics of expansion) are presented. This study has confirmed the risk of a significant expansion associated to DEF for a late heat treatment on concrete. A pessimum effect with the heating duration is highlighted. Keywords: concrete, DEF, late heat treatment, pessimum effect, expansion mechanism. 171

173 15ICAAR2016_089 EFFECT OF TEMPERATURE AND CURING DURATION OF EARLY HEAT TREATMENTS ON THE RISK OF EXPANSION ASSOCIATED WITH DELAYED ETTRINGITE FORMATION Kchakech B. 1, Martin R.-P. 1, Omikrine-Metassi O. 1, Renaud J.-C. 1, Baron L. 1, Toutlemonde F. 1 1 University Paris Est IFSTTAR- Materials and Structures Department, Boulevard Newton, Champs-Sur-Marne, Marne la Vallée Cedex 2 FRANCE Delayed Ettringite formation (DEF) is an autogenous expansive reaction that can affect concrete. Exposure to high temperature is a necessary condition to develop DEF. The results of experimental laboratory investigations that aim to quantify the effect of thermal history on DEF characteristics (namely magnitude and kinetics of expansion) are presented. A temperature threshold for the concrete at early age, a pessimum effect with respect to the heating duration and a relation between effective thermal energy and swelling parameters (kinetics and magnitude) are highlighted. Keywords: Concrete, expansion mechanism, DEF, Early age, Pessimum effect 172

174 15ICAAR2016_106 COMBINED ATTACK FROM AAR AND DEF IN THE FOUNDATION BLOCKS OF A BUILDING Nicole P. Hasparyk 1, Selmo C. Kuperman 2, José Ramalho Torres 3 1 ELETROBRAS Furnas, Gerência de Pesquisa, Serviços e Inovação Tecnológica, Goiânia, GO, BRAZIL 2 DESEK, São Paulo, SP, BRAZIL 3 NUTEC, Fortaleza, CE, BRAZIL Quality and durability of concrete structures can be considerably affected by chemical attacks. This situation can lead structures to risks of performance and safety. Inspections and routine tests can not always infer the reality of the structure and sometimes supplementary laboratory tests are necessary to assist a correct diagnosis of the pathologies. Field inspections and compressive strength tests several times are neither enough nor conclusive. Furthermore, causes of deterioration are commonly attributed to just one factor, i.e., an alkali-aggregate reaction (AAR), a sulfate attack, or a corrosion incidence. The fact is that results of more detailed investigations have shown the potential deterioration of concrete structures by an association of AAR and DEF (Delayed Ettringite Formation). This paper will describe a real case of associated attack (AAR+DEF), presenting some lab supplementary tests and analyses that had led to a correct diagnosis of those pathologies in the foundation blocks of a residential building, in Brazil. Repair and rehabilitation through crack grouting and use of reinforced and prestressed concrete were performed and will also be presented. Keywords: Pathology, deterioration, concrete, AAR, DEF, repair. 173

175 15ICAAR2016_193 ASR AND DEF IN CONCRETE FOUNDATIONS IN THAILAND Viggo Jensen 1, and Suvimol Sujjavanich 2 1 Norwegian Concrete and Aggregate Laboratory LTD, Sorgenfrivein 11, 7031 Trondheim, NORWAY. 2 Kasetsart University, Faculty of Engineering, Department of Civil Engineering, 50 Paholyothin Rd. Chatuchak, Bangkok 10900, THAILAND Deleterious Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF) occur in concrete foundations from a major highway structure located in Thailand. ASR is caused by reaction from slow reactive sericite rock, quartzite and granite with and without cataclastic texture reported by the authors in a separate paper. SEM/EDX analyses from the same concretes presented in this paper give information on the appearance of reaction products and chemical composition compared with Norwegian reaction products and internationally. In the concretes DEF and ASR were observed. Examination of the sequential appearance of DEF and ASR shows that DEF appears first and is succeeded by ASR. It is suggested that DEF might have activated slow reactive aggregates to be alkali reactive and hereby triggered ASR. This because Thai cements have a very low alkali content and slow reactive aggregates normally require high alkali content to be alkali reactive and react in the concrete. Keywords: Concrete, Alkali Silica Reaction (ASR), Delayed Ettringite Formation (DEF), Petrography, Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/ EDX) 174

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