Effects of Temperature and Fly Ash on Compressive Strength and Permeability of High-Performance Concrete*

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1 Center for By-Products Utilization Effects of Temperature and Fly Ash on Compressive Strength and Permeability of High-Performance Concrete* By Tarun R. Naik, William A. Olson, Jr., and Shiw S. Singh Report No. REP-245 October 1994 Department of Civil Engineering and Mechanics College of Engineering and Applied Science THE UNIVERSITY OF WISCONSIN MILWAUKEE

2 EFFECTS OF TEMPERATURE AND FLY ASH ON COMPRESSIVE STRENGTH AND PERMEABILITY OF HIGH-PERFORMANCE CONCRETE* By Tarun R. Naik, Ph.D, P.E. Director, Center for By-Products Utilization William A. Olson, Jr., P.E. Research Associate, Center for By-Products Utilization and Shiw S. Singh, Ph.D., P.E. Post-Doctoral Fellow, Center for By-Products Utilization Department of Civil Engineering and Mechanics, College of Engineering and Applied Science, University of Wisconsin-Milwaukee P.O. Box 784, Milwaukee, WI Telephone: (414) FAX: (414)

3 *For presentation at the ACI 1994 International Conference on High-Performance Concrete, November 15-18, 1994, Singapore. OBJECTIVE The major objective of this study was to investigate the effects of curing environments on performance of high-performance of (HPC). The performance factors considered were : (1) Strength, (2) Permeability, (3) Workability, and (4) Cost. Two different curing environments, namely moist curing and Variable Temperature Curing Environments (VTCE) were used.

4 EXPERIMENTAL PROGRAM Mixture Proportions Two concrete mixtures (12.5P and 12.5E) were proportioned to have a 28-day design strength of 85 MPa (12,500 psi). The 12.5P mixture was proportioned to contain 20% Class C fly ash, and 5% silica fume. The 12.5E mixture was composed of approximately 30% Class C fly ash and 20% Class F fly ashes. The details of mixture proportions are given in Tables 1 and 2.

5 CONCRETE PROPERTIES TESTED Slump Air Content Density (Fresh and Hardened) Compressive Strength Chloride Ion Permeability Air Permeability Water Permeability

6 CONCLUSIONS COMPRESSIVE STRENGTH (1) Mixture 12.5P, with 20% Class C fly ash and 5% silica fume, achieved higher strength than the Economical Mixture 12.5E at all ages for specimens cured in the moist room and VTCE. The economical concrete mixture contained approximately 30% Class C and approximately 20% Class F fly ashes.

7 (2) The 12.5P mixture, achieved higher rates of strength gain at early ages when cured in the VTCE compared to moist curing. (3) Beyond the 28-day age, the compressive strength of the 12.5E mixture was relatively unaffected by the types of curing environments used in this work.

8 PERMEABILITY (1) In general, the chloride ion permeability/diffusion decreased with an increase in the amount of pozzolanic additives. (2) The Variable Temperature Curing Environment (VTCE) improved on the ability of the concrete to resist chloride ions pentration. (3) Generally, as the concrete compressive strength increased the chloride ion permeability decreased for specimens cured in both the environments.

9 (4) The Variable Temperature Curing Environment (VTCE), with a range of temperatures similar to the range of temperatures used in this investigation, improved the ability of the high-performance concretes to resist chloride ions penetration. (5) The Figg method was found to be inadequate to measure air and water permeability of the HPCs used in this work.

10 Table 1 Concrete Batch Proportions for Mixture 12.5P 12,500 psi Proven Mix Batch Proportions Mix Number 12.5P1 12.5P2 12.5P3 12.5P4 Design Strength, psi Cement, lbs/cu yd Fly Ash ("C"), lbs/cu yd Fly Ash ("F"), lbs/cu yd Silica Fume, lbs/cu yd Water, lbs/cu yd Sand (SSD), lbs/cu yd /4" Aggregate (SSD), lbs/cu yd Water-to-Cementitious Materials Ratio HRWRA, liq-oz/cu yd Retarder, liq-oz/cu yd Slump, inches 4½ 3½ 6¾ 7 Air Content, % Air Temperature, F Concrete Temperature, F Concrete Density, pcf

11 Table 2 Concrete Batch Proportions for Mixture 12.5E 12,500 psi Economical Mix Batch Proportions Mix Number 12.5E1 12.5E2 12.5E3 12.5E4 Design Strength, psi Cement, lbs/cu yd Fly Ash ("C"), lbs/cu yd Fly Ash ("F"), lbs/cu yd Silica Fume, lbs/cu yd Water, lbs/cu yd Sand (SSD), lbs/cu yd /4" Aggregate (SSD), lbs/cu yd Water-to-Cementitious Materials Ratio HRWRA, liq-oz/cu yd Retarder, liq-oz/cu yd Slump, inches 9½ 9½ 10 9¼ Air Content, % Air Temperature, F Concrete Temperature, F Concrete Density, pcf

12 Table 3 Compressive Strength Test Results for Mixture 12.5 P and Mixture 12.5E Subjected to Moist Room and Variable Temperature Curing Environments Test Moist Room Lab Cured Variable Temperature Cured Age, 12.5P Mixture 12.5E Mixture 12.5P Mixture 12.5E Mixture Days Actual Average Actual Average Actual Average Actual Average

13 Table 4 Rapid Chloride Ion Test Results For Mixture 12.5P and 12.5E Specimens Cured in the Moist Room Mix No. Age (days) Specimen No. Total Charge Passed, Coulombs Average Charge Passed, Coulombs 12.5P P P E E E

14 Table 5 Rapid Chloride Ion Test Results for Mixture 12.5P and 12.5E Specimens Subjected to a Variable Temperature Curing Environment Mix No. Age (days) Specimen No. Total Charge Passed, Coulombs Average Charge Passed, Coulombs 12.5P P P E E E

15 MOIST CURING ENVIRONMENT IN THE CBU LABORATORY

16 VARIABLE TEMPERATURE CURING ENVIRONMENT

17 COMPRESSION TESTING MACHINE

18 RAPID CHLORIDE ION PERMEABILITY TESTING MACHINE

19 FIGG AIR PERMEABILITY TEST

20 FIGG WATER PERMEABILITY TEST

EXPERIMENTAL INVESTIGATION ON BEHAVIOUR OF NANO CONCRETE

EXPERIMENTAL INVESTIGATION ON BEHAVIOUR OF NANO CONCRETE International Journal of Civil Engineering and Technology (IJCIET) Volume 7, Issue 2, March-April 2016, pp. 315 320, Article ID: IJCIET_07_02_027 Available online at http://www.iaeme.com/ijciet/issues.asp?jtype=ijciet&vtype=7&itype=2