MODEL CLAUSES FOR CIVIL ENGINEERING WORKS

MODEL CLAUSES FOR CIVIL ENGINEERING WORKS SECTION 80 STRUCTURAL CONCRETE Contents Page 80.001 Application of standards and codes of practice 3 80.002 Classification of concrete mixes generally 3 80.003 Cement for ordinary structural concrete 3 80.004 Cement for special structural concrete 4 80.005 Cement replacement 4 80.006 Aggregate for ordinary structural concrete 5 80.007 Aggregate for special structural concrete 6 80.008 Water 7 80.009 Admixtures 7 80.010 Miscellaneous aggregates 9 80.011 Concrete grade 9 80.012 Minimum cement content and maximum water/cement ratio 10 80.013 Maximum chloride content 10 80.014 Maximum sulphate content 10 80.015 Control of alkali silica reaction 10 80.016 Current margin for designed mixes 11 80.017 Suitability of proposed mix proportions 12 80.018 Trial mixes 13 80.019 Concrete production 14 80.020 Batching and mixing 16 80.021 Ready-mixed concrete 16 80.022 Compliance with specified requirements generally 17 80.023 Compliance with specified strength requirement 17 80.024 Compliance with workability requirements 19 80.025 Air content of fresh concrete 19 80.026 Tests on concrete for other purposes 20 80.027 Records 20 80.028 Trial panel 20 80.029 Release agents 21 80.030 Surface finishes 21 80.031 Surface impregnation 24 80.032 Construction joints 28 80.033 Formwork 28 80.034 Additional requirements for controlled permeability formwork 29 80.035 Transporting, placing and compacting of concrete 30 80.036 Striking formwork 31 80.037 Curing 31 80.038 Accelerated curing 32 80.039 Additional requirements for mass concrete pours 33 80.040 Additional requirements for in situ concrete 35 80.041 Precast concrete construction 35 80.042 Grouting of prestressing tendons 37 80.043 Reinforcement materials 38 80.044 Bar schedule dimensions 38 80.045 Fixing 39 Page 1 of 50

80.046 Reinforcement laps and joints 39 80.047 Welding of reinforcement 40 80.048 Prestressing tendons materials 40 80.049 Positioning of tendons, sheaths and ducts 41 80.050 Tensioning the tendons 41 80.051 Protection of tendons 42 80.052 Supervision of prestressing operations 42 80.053 Steel fibre for reinforced concrete generally 42 80.054 Steel fibre for track slabs and hardstandings 43 80.055 Steel fibre for sprayed concrete 43 80.056 Concrete with steel fibres for track slabs and hardstandings 43 80.057 Synthetic fibre reinforcement concrete 44 80.058 Requirements for sprayed concrete 44 80.059 Floor construction 47 80.060 Early age grinding 48 80.061 Power floating 48 49 References British Standards 53 Other publications 50 Model Clauses 50 Page 2 of 50

SECTION 80 Application of standards and codes of practice STRUCTURAL CONCRETE 80.001 Concrete shall be produced and placed in accordance with this Section when it is used for all structural concrete except as identified in Section 85 of the Model Clauses. Concrete and the constituent materials shall comply with BS 5400: Part 7:1978 except where qualified, amended or replaced by the following Clauses. All numbers in parentheses within the heading margin are the relevant clause numbers within BS 5400: Part 7:1978. Classification of concrete mixes generally (3.1.1) 80.002 Delete BS 5400: Part 7, clause 3.1.1, and the following Structural concrete shall be a designed mix, and shall be either ordinary structural concrete or special structural concrete. (3.7) Delete BS 5400: Part 7, clause 3.7. Each concrete mix shall be in accordance with Schedule 80/A, in Appendix 80/1. Cement for ordinary structural concrete (3.2.1) 80.003 Delete BS 5400: Part 7, clause 3.2.1, and the following shall apply: Cement for ordinary structural concrete shall be one of the following: (i) Portland cement to BS EN 197-1:2000, (CEM 1), (ii) Portland blast furnace cement to BS EN 197-1:2000 (CEM 111A, CEM 111B), (iii) (iv) (v) (vi) Sulphate resisting Portland cement to BS 4027:1996 (SRPC), Portland pulverised fuel ash (PFA) cement to BS EN 197-1:2000 (CEM 11A, CEM 11B), Portland cement to BS EN 197-1:2000 mixed with PFA in accordance with BS EN 450-1+A1:2007, subject to the limits specified in BS 5400:Part 7 and Clause 80.005 (C11B, C1V B), Portland cement to BS EN 197-1:2000 mixed with ground granulated blast furnace slag to BS 6699 subject to the limits specified in BS 5400:Part 7 and Clause 80.005 (C11, C111A, C111B). Page 3 of 50

All Portland cements shall be obtained from a company that has a quality system for product conformity approved in accordance with BS EN ISO 9001 by a body accredited by the United Kingdom Accreditation Service (UKAS) or equivalent. Cement for special structural concrete (3.3.1) 80.004 Delete BS 5400: Part 7, clause 3.3.1, and the following shall apply: Cement for special structural concrete shall comply with Clause 80.003 or, subject to the agreement of the Employer s Representative, with the following: (i) high alumina cement to BS EN 14647: 2005. High alumina cement shall only be used where early and rapid strength gain is required, and the required strength gain cannot be obtained using the other cements specified in this Clause with, where appropriate, an accelerating admixture to BS EN 934-2:2001, (ii) low heat Portland cement to BS 1370, (iii) high slag blast furnace cement to BS EN 197, (iv) Portland cement to BS EN 197-1:2000 mixed with ground granulated blast furnace slag to BS 6699 subject to the limits specified in Clause 80.005, (v) modified Portland cements to BS EN 197-1:2000, (vi) Portland cement to BS EN 197-1:2000 mixed with additional silica fume slurry having a current British Board of Agrément certificate and source accepted by the Employer s Representative, subject to the limits specified in Clause 80.005. Cement replacement 80.005 Pulverised fuel ash (PFA) used as a cement replacement shall not be less than 21% or more than 35% by weight of the total cementitious content, except as qualified below. The maximum limit of PFA may be increased to 55% provided that the resultant concrete will have a minimum strength class of C20/25, a maximum water cement ratio of 0.65, a minimum cement content of 260 kg/m³ and the concrete is to be either: (i) (ii) located below final ground level, located permanently underwater, Page 4 of 50

(iii) coated by an approved protective treatment which inhibits the passage of carbon dioxide. Cement replacement in sprayed concrete shall not exceed the limits specified in the 'European Specification for Sprayed Concrete' published by the European Federation of Specialist Construction Chemicals and Concrete Systems (EFNARC). Where PFA is proposed to be used in the concrete mix, the Employer s Representative shall be provided with a certificate to show that the material is in accordance with BS EN 450-1:2005+A1:2007, with the grading and name of the power station. Ground granulated blast furnace slag (ggbs) used as a cement replacement in ordinary structural concrete shall not exceed 65% by weight of the total cement. Ggbs used as a cement replacement in special structural concrete shall not be less than 50% or more than 80% by weight of the total cement. Where ggbs is proposed to be used in a concrete mix, the Employer s Representative shall be provided with a certificate to show that the material complies with BS 6699. Silica fume used in special structural concrete shall not exceed 15% by weight of the total cement. Aggregate for ordinary structural concrete (3.2.2) 80.006 Delete BS 5400: Part 7, clause 3.2.2, and the following Aggregates for ordinary structural concrete shall be one of the following: (i) (ii) aggregates from natural sources to BS EN 12620:2002, as qualified by this Clause, air cooled blast furnace slag to BS EN 12620:2002. When air cooled blast furnace slag is included in the concrete mix, the aggregate shall be sampled and tested at a frequency agreed with the Employer s Representative to confirm its bulk density. Where significant variation from that used in the mix design is found, the mix shall be adjusted to allow for the variation in the bulk density of the aggregate. Page 5 of 50

The shell content of the aggregates included as calcium carbonate determined in accordance with BS 812-106:1985 shall not exceed the values stated in BS EN 12620:2002. Where no nominal maximum size of aggregate is specified in Schedule 80/A the nominal maximum size of the aggregate shall be as specified below such that the concrete can be placed and compacted around the reinforcement without segregation. The nominal maximum size of the aggregate shall not exceed: (i) (ii) (iii) 0.25 x the smallest dimension of the structural member, the clear distance between reinforcing bars less 5mm, or 0.75 x the clear distance between reinforcing bars, whichever is the less, 0.75 x the concrete cover. The chloride levels of the aggregates shall be determined in accordance with BS 812-117:1988 at a frequency agreed with the Employer s Representative. The flakiness index of the coarse aggregate determined in accordance with BS 812-105.1: 1989 shall not exceed 40%, except for natural, uncrushed aggregates included in concrete grade 40 or lower, when the flakiness index shall not exceed 50%. No limit shall apply to concrete grade C12/15 or less. The drying shrinkage determined in accordance with BS 812-120:1989 shall not exceed 0.075%. Aggregate for special structural concrete (3.3.2) 80.007 Delete BS 5400: Part 7, clause 3.3.2, and the following shall apply: Aggregates for special structural concrete shall comply with Clause 80.006 except that aggregate to BS EN 12620:2002 shall not be used with high alumina cement. Lightweight aggregate shall be in accordance with BS EN 13055-1:2002. Page 6 of 50

Water (3.2.3) 80.008 Delete BS 5400: Part 7, clause 3.2.3 and the following Water for use in the concrete mix shall be clean and free from harmful matter and, where possible, shall be obtained from a water supply company. Should the Contractor wish to use any other source of water, the Employer s Representative shall be advised of the proposed source, and the water shall be tested in accordance with BS EN 1008 at a frequency agreed with the Employer s Representative. Such water shall not be incorporated in the Works without the agreement of the Employer s Representative. If the ph value of such water is less than 4, the water shall not be incorporated in the concrete mix. The sodium oxide and potassium oxide content of such water shall be reported to the Employer s Representative, and shall be taken into account when calculating the total reactive alkali content of the concrete mix in accordance with Clause 80.015. Admixtures (3.3.4) 80.009 Delete BS 5400: Part 7, clause 3.3.4.1, and the following The quantity and method of use of admixtures shall be in accordance with the manufacturer s recommendations and shall be subject to the agreement of the Employer s Representative. Except when used in sprayed concrete, admixtures in a concrete mix shall not exceed 50g/kg of cement nor, unless dispersed in the mixing water, be less than 2g/kg of cement. Liquid admixtures in excess of 3 litres/m 3 shall be taken into account when calculating the water/cement ratio. Accelerating admixtures to be used in sprayed concrete shall not exceed the following: (i) (ii) powder admixtures: 6% of cementitious material by weight, liquid admixtures: 8% of cementitious material by weight. Page 7 of 50

When used in a grout mix, the optimum dosage of the admixture shall be determined by trial mixes with the cement to be used in the grout. The dosage shall be within the range recommended by the supplier and shall not exceed 5% by mass of the cement. The method of measuring dosage and checking the weights of pre-packed dry materials shall be agreed with the Employer s Representative. Admixtures shall comply with one of the following: (i) pigments to BS EN 12878:2005, (ii) accelerating, retarding or water reducing admixtures to BS EN 934-2:2001, (iii) air entrainment admixtures to BS EN 934-2:2001, (iv) superplasticizers to BS EN 934-2:2001. Admixtures not included in BS EN 12878 or BS EN 934-2:2001 shall be permitted provided that such admixtures comply with the requirements for identification, compatibility, chloride content and alkali content included in this Section and that: (i) (ii) full account of their effect on the finished concrete is taken in determining the concrete mix, there are sufficient data regarding their suitability, including previous use in similar concrete mixes and applications. Admixtures shall not impair the durability of the concrete or grout nor increase the risk of corrosion of reinforcement. Thiocyanate, nitrates, formate and sulphides shall not be included in admixtures. Admixtures shall be manufactured and supplied by a company which has a quality system for product conformity approved in accordance with BS EN ISO 9001 by a body accredited by the United Kingdom Accreditation Service (UKAS) or equivalent. For each proposed admixture the Employer s Representative shall be supplied with the following information: (i) proposed dosage rate per 100 kg of cement, Page 8 of 50

(ii) (iii) (iv) (v) details of the effects of underdosage and overdosage, generic type of the active constituents in the admixture, whether or not for the proposed dosage the admixture leads to entrainment of air, where two or more admixtures are to be used in the same concrete mix, information on the interaction and compatibility of the admixtures, including confirmation obtained from each respective admixture manufacturer on the compatibility of the admixtures to be used. Where practicable, admixtures for inclusion in a concrete mix shall be added at the batching plant. Admixtures for inclusion in grout may be added at Site. Admixtures shall not be used with high alumina cement. Miscellaneous aggregates (3.4) 80.010 In BS 5400: Part 7, clause 3.4.1, delete reference to BS 877, and amend reference to BS 882 (coarse 3 and 4) to BS 882, table 4, Zones M or F. Delete BS 5400: Part 7, clause 3.4.2 and the following Aggregate for use as a concrete wearing surface shall be in accordance with the Manual of Contract Documents for Highway Works, Volume 1, Specification for Highway Works, Series 1000. Concrete grade (3.5.1) 80.011 Delete BS 5400: Part 7, clause 3.5.1 and the following The compressive strength grade of the concrete shall be in accordance with the design assumptions as detailed in Schedule 80/A of Appendix 80/1 and also with BS 8500-1:2002 Clause A7. The minimum strength grade shall be in accordance with BS 8500-1:2002 clause A5. The class of concrete shall be specified by the grade and nominal maximum aggregate size. Page 9 of 50

Minimum cement content and maximum water/cement ratio (3.5.2) 80.012 The minimum cement content shall be not less than the minimum stated in BS 8500-1:2002 clause A5 appropriate to the condition exposure, sulphate class of the surrounding soil or water, and cement type, as modified by BS 8500-1:2002 clause A5 according to the nominal maximum aggregate size. For reinforced concrete below ground level, the minimum cement content shall be 300 kg/m 3. Where concrete is to be placed under water or is to support fluid, the minimum cement content shall be 380 kg/m 3. Concrete that will be exposed to sea water shall have a minimum cement content not less than 400 kg/m 3. The maximum water/cement ratio shall be in accordance with BS 8500-1:2002 Clause A5 appropriate to the condition exposure and sulphate class of the surrounding soil or ground water. The minimum cement content when high alumina cement to BS EN 14647:2005 is used shall be 400 kg/m³, and the maximum water/cement ratio mix shall be 0.40. For the limits specified in this Clause, the minimum converted strength should not be less than 32/40 N/mm². (3.9.3, 3.9.5) Delete BS 5400: Part 7, clauses 3.9.3 and 3.9.5. Maximum chloride content Maximum sulphate content Control of alkalisilica reaction 80.013 The total chloride content of a concrete mix from the cement, aggregate and any other source shall not exceed the relevant limit stated in BS 8500-1:2002 Clause A9 determined in accordance with BS 812-117:1988. 80.014 The maximum sulphate content of a concrete mix expressed as sulphuric anhydride (SO 3 ) shall not exceed 4 % by weight of cement. The sulphate content shall be calculated from the sulphate content of the concrete mix constituents in accordance with the relevant British Standard for the constituent. 80.015 Except where all the aggregates to be used in the concrete mix have been certified by a qualified chemist competent in concrete chemistry as having normal or low reactivity as defined in clauses 19.2(a) to 19.2(c) of the Concrete Society s Technical Report No. 30, the reactive alkali content of the concrete mix shall not exceed 3 kg/m³. Page 10 of 50

The reactive alkali content of the concrete mix, in terms of sodium oxide equivalent (Na 2 O), shall be expressed as specified in BS 8500-1:2002 Annex C, using the guaranteed alkali limits of the constituents of the concrete mix. The Employer s Representative shall be provided with copies of test certificates showing the average value of the acid soluble alkali content determined in accordance with BS EN 196-2:2005 for: (i) (ii) cement during the period of manufacture, any pulverised fuel ash or ground granulated blast furnace slag for the preceding 25 week period. The equivalent sodium oxide content of the aggregate shall be calculated from the quality of chloride ion present measured in accordance with BS 812-117:1988. Current margin for designed mixes (3.6.1) 80.016 In addition to BS 5400: Part 7, clause 3.6.1, for concrete up to grade C12/15, the current margin for a designed mix shall be determined by the Contractor and shall be taken as the lesser of: (a) (b) 1.64 times the standard deviation of cube compressive strength test results on at least 100 separate batches of concrete of nominally similar proportions of similar materials and produced over a period not exceeding 12 months, by the same plant under similar supervision, but not less than one sixth of the characteristic strength for concrete up to grade 12/15 or 3.0/3.75 N/mm 2 for concrete of grade 16/20 or above. 1.64 times the standard deviation of cube compressive strength test results on at least 40 separate batches of concrete of nominally similar proportions of similar materials and produced over a period not less than 5 days but not exceeding 6 months, by the same plant under similar supervision, but not less than one third of the characteristic strength for concrete up to grade 12/15 or 6.0/7.5 N/mm 2 for concrete of grade 16/20 or above. Page 11 of 50

Where there is insufficient data to satisfy sub-clauses (a) or (b) above, the margin for the initial mix design shall be taken as two thirds of the characteristic strength for concrete up to grade 12/15 or 12/15 N/mm 2 for concrete of grade 16/20 or above. This margin shall be used as the "current margin" only until sufficient data are available to satisfy sub-clauses (a) or (b) above. However, when the specified characteristic strength approaches the maximum possible strength of concrete made with a particular aggregate, a smaller margin (not less than one third of the characteristic strength for concrete up to grade 12/15 or 6.0/7.5 N/mm 2 for concrete of grade 16/20 or above) may be used for the initial mix design. Suitability of proposed mix proportions (3.6.2) 80.017 Delete the alternative specified in BS 5400: Part 7, clause 3.6.2(b)(3), and the last paragraph of BS 5400: Part 7, clause 3.6.2. The following paragraphs shall apply. The types and sources of cement, aggregates, pulverised fuel ash, and ground granulated blast furnace slag to be included in the concrete mix shall be agreed by the Employer s Representative. The cement type used in the concrete mix shall be suitable for the application of the concrete (plain, reinforced, post-tensioned or prestressed), the heat development in the concrete mass, the dimensions of the structure, and the sulphate class listed in BS 8500-1:2002 Clause A5. In addition the concrete mix shall be selected to satisfy all the performance criteria for fresh and hardened concrete, and to give a workability consistent with the proposed method of construction. The concrete mix shall minimise segregation, permeability, bleeding, plastic settlement, shrinkage and thermal cracking, and shall produce the surface finishes specified on the Contract Drawings and in accordance with Clause 80.030. Where practicable, plastic settlement, shrinkage and thermal cracking shall be minimised by the use of pulverised fuel ash or ground granulated blast furnace slag in accordance with Clause 80.005 and provided the use of such materials has no deleterious effects. Synthetic fibres included in the mix to limit plastic settlement, plastic shrinkage, thermal cracking, or as an alternative to air entrainment for freeze/ thaw resistance, shall comply with Clause 80.057. Page 12 of 50

Where the proposed concrete mix is to be pumped, the Employer s Representative shall be provided with evidence that the mix can be pumped without segregation, bleeding or persistent blockages. For a concrete mix specified to be suitable for water impermeable concrete, the resistance to water penetration when tested according to BS EN 12390-8:2000 shall have a maximum penetration of less than 50 mm, and mean average values of penetration less than 20 mm. The water/cement ratio shall not exceed 0.55. Any change in the source of the concrete mix constituent material or in mix proportions, shall be agreed by the Employer s Representative, except changes in total cementitious material content of not more than 20 kg/m³, and where included changes in the content of pulverised fuel ash or ground granulated blast furnace slag of not more than 10 kg/m³. Trial mixes (3.6.3) 80.018 Further to BS 5400: Part 7, clause 3.6.3, trial mixes are not required for concrete where the concrete supplier can demonstrate to the Employer s Representative that, for the proposed concrete mix, 40 recent test and sampling results for a related mix (including admixtures, where applicable), confirm the attainment of the specified strength, including early high strength where applicable, within the current margin in accordance with the Clause 80.016. Where trial mixes are not proposed to be carried out, the following information shall be provided to the Employer s Representative: (i) (ii) (iii) (iv) confirmation that the relationship for the family of mixes exists and is current, the 40 most recent results for the materials at the reference mix level that exist to justify the reference mix cement content (results at the reference mix or transformed to the reference mix), the difference in the cement content of the reference mix, and the specified mix, confirmation that the data has been produced in accordance with the Quality Scheme for Ready- Mixed Concrete Regulations. Where the above information for a concrete mix cannot be provided, trial mixes shall be carried out. Page 13 of 50

Where trial mixes are carried out to demonstrate high early strength, for each mix a set of nine test cubes shall be made from each of three consecutive batches. Test cubes shall be tested at the following ages: (i) 8 hours, or as specified in Appendix 80/2, (ii) (iii) 24 hours, 28 days. For any trial mix the average strength of the nine cubes tested at 28 days shall exceed the specified characteristic strength by the lesser of: (i) (ii) 11.5 N/mm², or, the current margin less 3.5 N/mm². Where high alumina cement to BS EN 14647:2005 is used in the mix, three additional cubes shall be taken, and shall be subjected to an agreed accelerated curing regime, and tested to determine the converted strength. Trial mixes of proposed concrete mixes shall demonstrate the workability of the concrete mix and the action of admixtures and/or silica fume slurry, and shall prove the ability of the proposed concrete mix to attain the specified characteristic strength. Trial mixes shall be carried out a minimum of six weeks before the concrete is programmed to be incorporated in the Works. The workability of each batch of the concrete mix shall be tested three times at equal intervals within one hour of mixing using one of the methods appropriate to the workability of the concrete mix specified in Clause 80.024. Concrete production (3.8.2) 80.019 Delete BS 5400: Part 7, clause 3.8.2, and the following Cement, pulverised fuel ash, and ground granulated blast furnace slag shall be stored and used in accordance with BS 8500-2:2002 clause 11. The Employer s Representative shall be provided with a certificate confirming that the cement complies with the relevant British Standard, and including results of tests carried out to verify such compliance. Page 14 of 50

(3.8.3) Further to BS 5400: Part 7, clause 3.8.3, for each aggregate type proposed to be used, the Employer s Representative shall be provided with all the information listed in BS EN 12620:2002 Annex A, and a copy of the relevant test results. For concrete with exposed faces, surface-marring aggregates such as pyrites shall not be used. Concrete to be placed in situ or to form precast concrete units to be constructed at the Site shall be produced only from a batching plant holding current Quality Scheme for Ready-Mixed Concrete certification for product conformity except as follows: (i) (ii) dry process sprayed concrete, concrete pours less than 3 m³, (iii) as specified in Appendix 80/3. For concrete produced by an on-site batching plant, prior to any concrete being placed in the Works, the Employer s Representative shall be provided with confirmation of the concrete supplier s quality assurance certification in accordance with BS 8500-2:2002 clause A5 and a copy of the certification for product conformity for the site batching plant. Concrete for precast concrete units to be constructed offsite shall be produced either by a batching plant holding current Quality Scheme for Ready-Mixed Concrete certification for product conformity, or at the precast concrete manufacturer s works where the Contractor can demonstrate that concrete production is included in the quality system for product conformity specified in Clause 80.041. Lightweight concrete such as foamed concrete shall be produced under controlled conditions by blending cement in accordance with Clause 80.004, sand, and water with a foaming admixture to produce a free flowing, self levelling, non combustible lightweight concrete with a density not exceeding 1200 kg/m 3. Page 15 of 50

Batching and mixing (3.8.4) 80.020 References to cement in BS 5400: Part 7, clause 3.8.4 shall be deemed to include all the cementitious materials listed in Clauses 80.003 and 80.004. In addition to BS 5400: Part 7, clause 3.8.4, the following All concrete mix constituents shall be thoroughly mixed together to produce a concrete mix with a homogeneous consistency. Admixtures and steel or synthetic fibres included in the concrete mix shall be distributed evenly throughout each batch. No concrete mix shall be altered after the concrete has left the mixer. Where water with a temperature in excess of 60 C is used, the water shall be mixed with the aggregate before coming into contact with the cement. Water in excess of 80 C shall not be used. Where lightweight aggregate is specified, the density of the concrete shall not exceed 1850 kg/m 3. The requirements of BS 5400: Part 7, clause 3.8.4 shall be amended as follows. The quality of water in the mix, and the batch weight of the aggregate shall be adjusted to allow for the free moisture content of the aggregate. Delete references to BS 1305 (Batch type concrete mixers), and BS 4251 (Truck type concrete mixers). Mixers shall be capable of uniformly distributing the constituent materials to obtain a uniform workability within the mixing time and at the mixing capacity. Ready-mixed concrete (3.8.6) 80.021 In addition to BS 5400: Part 7, clause 3.8.6, the following Ready-mixed concrete shall only be supplied from a batching plant holding current Quality Scheme for Ready- Mixed Concrete certification for product conformity. The Employer s Representative shall be provided with confirmation of the concrete supplier s quality assurance certification in accordance with BS 8500-2:2002 and a copy of the certification for product conformity for the batching plant. Verification of the certification shall be obtained from: Page 16 of 50

Quality Scheme for Ready-Mixed Concrete 1 Mount Mews High Street Hampton Middlesex TW12 2SH Tel: 020 8941 0273 Fax: 020 8979 4558 www.qsrmc.co.uk Delete reference to BS 4251 in BS 5400: Part 7, clause 3.8.6. Truck mixers shall be capable of delivering the concrete in a homogenous mixed state. Water and admixtures shall be added under supervision either at the Site or at the batching plant. No water shall be added in transit or on site if the water was originally added at the batching plant. Truck mixers shall be equipped with appropriate measuring and dispensing equipment. Compliance with specified requirements generally (3.9.1) Compliance with specified strength requirement (3.9.2) 80.022 In addition to BS 5400: Part 7, clause 3.9.1, the following Testing of fresh and hardened concrete and constituent materials shall be carried out by an organisation accredited by the United Kingdom Accreditation Service (UKAS) for the relevant tests. All details of the company proposed to be used shall be submitted to the Employer s Representative for acceptance. 80.023 Delete BS 5400: Part 7, clause 3.9.2.1, and the following Where the Contractor is able to demonstrate in accordance with Clause 80.018 that a trial mix for the proposed mix is not required, compliance testing for specified strength requirements in accordance with BS 8500-1:2002 shall be carried out only for concrete of compressive strength grade C25/30 or greater. For all grades of concrete, where the Contractor is able to demonstrate in accordance with Clause 80.018 that a trial mix for the proposed mix is not required, the Employer s Representative shall be provided with a mix design certificate detailing the concrete mix constituents and their quantities, mix density, and confirming that for the proposed mix, the specified strength will be obtained within the current margin. Page 17 of 50

The mix design certificate shall also confirm: (i) (ii) (iii) (iv) that the relationship for the family of mixes exists and is current, that 40 results exist to justify the reference mix cement content, the difference in the cement content of the reference mix and the proposed mix, that the data has been produced in accordance with the Quality Scheme for Ready-Mixed Concrete Regulations. Where a mix design certificate for a concrete compressive strength grade C25/30 and above is provided, the minimum rate of sampling for compliance testing for specified strength requirements for each concrete mix shall be 100m³ or 100 batches with not less than one sample taken on each day that the concrete mix is used. Where a mix design certificate for a concrete compressive strength grade C25/30 and above cannot be provided, compliance testing for specified strength requirements shall be carried out at the rate of sampling in accordance with Table 80/1, with not less than one sample taken on each day that the concrete mix is used. Table 80/1 Type of concrete Sample from one batch selected to represent an average volume of not more than the lesser of: Prestressed or post-tensioned 10 m³ or 10 batches concrete, and reinforced concrete cantilevers Highly stressed parts of the 10 m³ or 10 batches works as specified in Appendix 80/4 All other reinforced concrete 20 m³ or 20 batches Mass concrete 50 m³ or 50 batches Sampling, curing and testing of fresh and hardened concrete shall be carried out in accordance with the requirements of BS EN 12350 Parts 1 to 7 and BS EN 12390 Parts 1, 2, 3 and 7. Conformity testing and conformity criteria shall be carried out in accordance with BS8500-2:2002 clause 10 and the relevant requirements of BS EN 206-1:2000. Page 18 of 50

Compliance with workability requirements (3.9.4) 80.024 Delete BS 5400: Part 7, clause 3.9.4, and the following The workability of the fresh concrete shall be such that the concrete is suitable for the conditions of handling and placing, so that after compaction, the concrete surrounds all reinforcement, prestressing tendons, ducts and steelwork without segregation and completely fills the formwork. Workability shall be measured for each batch of concrete or as directed by the Employer s Representative using one of the tests appropriate to the designed workability specified in BS EN 12350: Parts 2, 3, 4 or 5. Workability shall be within the tolerances stated in BS 8500-1:2002 Annex B of the design value. Air content of fresh concrete (3.9.6) 80.025 Delete BS 5400: Part 7, clause 3.9.6, and the following Concrete shall have a composition such that after compaction it has a closed structure, i.e. the air content by volume (entrained air and aggregate pores excepted) shall, when tested in accordance with BS EN 206-1 clause 5.4.3, be not more than: (i) (ii) 3% for aggregates 16 mm nominal size, 4% for aggregates <16 mm nominal size. Where air entrainment admixtures are included in the concrete mix, the mean air content of the fresh concrete by volume at the moment of delivery into the Works shall be: (i) (ii) (iii) (iv) 7.5% for natural aggregates 10 mm nominal size, 6.5% for natural aggregates 14 mm nominal size, 5.5% for natural aggregates 20 mm nominal size, 4.5% for natural aggregates 40 mm nominal size. For concrete required in accordance with Clause 80.023 to be tested for compliance with specified strength requirements, the air content shall be checked as described in BS EN 12350: Part 7 at the rate of sampling specified in Clause 80.023. The tolerance on the specified mean total air content shall be in accordance with BS 8500-1:2002 Annex B. Page 19 of 50

Tests on concrete for other purposes (3.9.7) 80.026 Further to BS 5400: Part 7, clause 3.9.7, for precast prestressed beams, test cubes shall be made equally from the concrete batches used in the first and last cast beam in each line of a pretensioning bed and tested in accordance with BS EN 12390: Parts 1 & 3 to confirm attainment of the concrete strength specified for transfer. For post-tensioned concrete, test cubes shall be made and tested in accordance with BS EN 12390: Parts 1 & 3 to confirm attainment of the concrete strength specified for stressing. The concrete shall be sampled at a rate sufficient to demonstrate that the required strength of the concrete at transfer has been reached, subject to a minimum of six test cubes. The test cubes shall be cured under conditions agreed by the Employer s Representative which shall simulate the conditions of the concrete member. Should the Contractor wish to take additional cubes for determining when formwork may be struck, such cubes shall be taken at no additional cost to Network Rail. Records 80.027 Records shall be kept of the positions in the Works of all batches of concrete from which samples for testing have been taken. Each test cube or cylinder shall have an identification placed upon it which shall be recorded together with the date of casting and the date at which the cube or cylinder was despatched to the laboratory for testing. The laboratory test report shall include all information specified to be provided in BS EN 12390-3:2002. All the information reported by the laboratory shall be added to the records kept by the Contractor and written confirmation of the test results provided to the Employer s Representative within 24 hours of completion of the tests. Trial panel (3.10.1) 80.028 Delete BS 5400: Part 7, clause 3.10.1, and the following When required in Appendix 80/5 and before commencing concreting the Contractor shall prepare a trial panel of a size stated that will demonstrate that the required surface finish can be achieved by the methods proposed. The panel shall contain representative reinforcement and shall be filled with the proposed concrete compacted by the method to be used in the Works. Page 20 of 50

As soon as practicable after compaction, the forms shall be removed to check that the required surface finish and compaction has been achieved. Release agents (3.10.3) 80.029 Delete BS 5400: Part 7, clause 3.10.3 and the following Release agents for the formwork shall enable the formwork to be removed without damage to the concrete surface. There shall be no adverse residual effect from the release agent on the concrete surface. Where the concrete surface is to be permanently exposed, only one agent shall be used throughout the entire area. Release agents shall be applied evenly and shall not be permitted to come into contact with reinforcement, prestressing tendons and anchorages. Any such contact shall be washed free of contamination. In addition, release agents shall not be permitted to come into contact with steel beams either internal or external to the concrete. Where concrete is to receive an applied finish, or surface impregnation, release agents shall be compatible with the particular process. Surface finishes (3.10.4) Formed surfaces 80.030 Delete BS 5400: Part 7, clause 3.10.4 and the following Formed finishes shall produce the following classes of finishes using formwork specified in Clauses 80.033 and 80.034. Class F1 The surface finish shall be as struck and free from voids, honeycombing or other large blemishes with no extra requirement. Class F2 The irregularities in the finish shall be no greater than those obtained from the use of wrought thickened square edged boards arranged in a uniform pattern. The finish is intended to be left as struck but shall be free from all but minor holes, fins, minor blemishes and surface discolourations. Formed surfaces that are to receive a waterproofing system shall be Class F2 finish with holes, fins, sharp irregularities in excess of 2 mm and other blemishes made good. The surface shall be prepared in accordance with the waterproofing manufacturer s specification. Page 21 of 50

Class F3 The surface shall be smooth and of uniform texture and appearance. The formwork lining shall leave no stain on the concrete and shall be so joined and fixed to its backing that it imparts no blemishes. It shall be the same type and obtained from only one source throughout any one structure. The Contractor shall make good any imperfections in the finish. Internal ties and embedded metal parts shall not be used. Class F4 The requirements for Class F4 are as for Class F3 except that internal ties and embedded metal parts shall be permitted. The ties shall be positioned only in rebates or in other positions as described in Appendix 80/6. Class F5 The requirements for Class F5 are as for Class F3 except that provision for the embedment of metal parts in the Permanent Works on a regular spacing, shall be allowed. For formed finishes providing a special featured finish including pronounced marking, the use of absorbent form liners, coarse aggregate finish or other treatment, a trial panel in accordance with Clause 80.028 shall be provided. Special featured formed finishes shall be constructed as described in Appendix 80/6 Where an exposed aggregate finish is specified the formwork shall be treated with a retarding agent acceptable to the Employer s Representative. Following the removal of the side forms the laitance shall be removed to a depth described in Appendix 80/6. A construction joint finish obtained in accordance with Clause 80.032 shall be provided to the sides of precast beams to form shear connected joints. Where an unformed surface of a bridge deck abuts the web of a steel girder, a trapezoidal rebate 20 mm deep, with base dimension 15 mm and upper dimension 35 mm, shall be provided to accommodate a movement joint seal in accordance with Sections 110-114: Waterproofing. Page 22 of 50

Unformed surfaces The following classification for unformed finishes shall apply. Class U1 The concrete shall be levelled and screeded to produce a uniform surface to the profile shown on the Contract Drawings. No further work shall be applied to the surface unless it is used as a first stage for another class of finish. Class U2 After the concrete has hardened sufficiently, the Class U1 finish shall be floated by hand or machine, sufficient only to produce a uniform surface free from screed marks. Class U3 When the moisture has disappeared and the concrete has hardened sufficiently to prevent laitance from being worked to the surface, a Class U1 finish shall be steel-trowelled under firm pressure to produce a dense, smooth uniform surface free from trowel marks. Class U4 The concrete shall be levelled and screeded to produce a uniform surface. When the concrete has hardened sufficiently and the bleed water evaporated, the surface shall be trowelled to produce a hard dense surface free from screed marks and exposed aggregate. Finally the surface shall be lightly textured with a wooden float or equivalent. Alternatively the concrete shall be levelled, screeded and floated to produce a uniform surface and immediately before the waterproofing operation this surface shall be prepared in accordance with the waterproofing manufacturer s specification. A Class U4 finish shall be used for a bridge deck which is to receive a sprayed waterproofing system. The finished surface shall not deviate from the required level by more than 10 mm over a 3.0 metre gauge length, or have any abrupt irregularities greater than 3 mm. Page 23 of 50

Class U5 The concrete shall be levelled and screeded to produce a uniform finish. When the concrete has hardened sufficiently to prevent laitance from being worked to the surface it shall be floated to produce a surface free from screed marks and exposed aggregate. Finally the surface shall be textured to suit the requirements of the particular waterproofing and surfacing system. The accuracy of the finished surface shall be such that it does not deviate from the required profile by more than 5 mm over a 3.0 metre gauge length, or have any abrupt irregularities. Other classes. The finishes shall comply with the specific requirements described in Appendix 80/6. Surface impregnation Material 80.031 The impregnation of reinforced, prestressed and posttensioned concrete structures using hydrophobic porelining impregnants (silane surface impregnation) shall be applied to the surfaces specified on the Contract Drawings in accordance with the manufacturer's instructions unless otherwise directed by Contract Documents or agreed by the Employer's Representative. The works shall, in addition, be carried out in accordance with Health and Safety requirements, COSHH requirements and Waste Disposal Authority requirements. The material for impregnation shall be monomeric alkyl (isobutyl)-trialkoxy-silane with a minimum active content of 92% delivered to the Site in sealed containers. Other materials shall only be used on the instruction of the Employer s Representative. Page 24 of 50

The refractive index of the material shall comply with the value stated in the manufacturer's product specification, within a limit of 0.003 units. The refractive index shall be checked as follows: 1) Collect samples of the material from a newly opened container and from the spraying nozzle. 2) Measure the refractive index of three samples from both the container and spray nozzle using a portable refractometer. 3) Measure the temperature of the samples (portable refractometers have temperature measuring capability). 4) Correct the refractive index measurements for the temperature stated in the manufacturer's product specification. 5) If the temperature corrected measured value of the refractive index exceeds the manufacturer's specified value by more than 0.003 units then a laboratory check shall be undertaken to confirm compliance. For each delivery, the Contractor shall provide a certificate confirming that the material complies with the material specification above. No material shall be used in the works until the Certificate of Compliance has been accepted by the Employer's Representative. The material shall be stored in a secure facility that has a dry, frost-free environment protected from direct heat. The containers shall remain sealed until their contents are required for use. The contents of any opened container shall be used within 48 hours or else disposed of safely as described later in this Clause. Materials offering a performance in respect of the protection of concrete and long term durability equivalent to that of monomeric alkyl (isobutyl)-trialkoxy-silane will be accepted. The assessment of the durability of an alternative surface applied hydrophobic pore lining impregnating material will be based on the provision of evidence that it has, in practice, provided an effective water repellent but vapour-permeable layer at the concrete surface for a period of not less than 15 years after application. Page 25 of 50

Spraying Equipment Protective Measures A power driven continuously circulating pumped system operating at a low nozzle pressure shall be used to apply the material in such a way as to avoid atomisation. Water shall be prevented from entering any part of the equipment. A pressure gauge shall be installed between the trigger valve and spray lance to enable the pressure to be monitored. A 'kill' switch shall be provided so that the pumping system may be stopped immediately should this be required. Use and handling of the silanes shall be in strict accordance with the manufacturer's recommendations, and in full compliance with all current Health and Safety legislation. The Contractor shall ensure that only fully trained operatives undertake impregnation operations, and where necessary carry out trials to verify procedures. Measures shall be taken to ensure that no impregnation material enters into any drainage system or watercourse. The Contractor shall obtain all necessary written permissions and licences from the appropriate authorities, prior to any silane operations above or adjacent to any watercourse. Measures shall be taken to ensure that no impregnation material comes into contact with any humans, animals, vegetation or vehicular traffic by providing suitable and adequate protection and traffic management. The Contractor shall obtain approval from the Employer's Representative and all other authorities' licenses, agreements and permissions associated with traffic safety, management and protective measures in advance of the commencement of impregnation operations. Elastomeric bearings, painted steel surfaces, exposed bituminous materials, and joint sealants adjacent to structural elements to be impregnated shall be masked off or covered before and during impregnation operations. In the case of spillage, action shall be taken immediately to limit the extent of the spillage and the Employer's Representative and other relevant authorities shall be informed at once. Surface Condition Areas to be treated shall be protected from any adverse effects of the weather and shall be surface dry for a minimum of 24 hours before application commences. Artificial drying of surfaces shall not be permitted. Page 26 of 50

Surfaces shall be free from loose or deleterious matter and residues of curing membranes, release agents, graffiti and graffiti removal agents (including any harmful residual effects from the application of curing membranes) before impregnation commences. Existing structures shall be hand brushed with a stiff bristle brush to remove surface deposits. Where deleterious surface deposits cannot be removed using a stiff bristle brush they shall be removed by light grit blasting. Water jetting or steam cleaning shall not in general be used as a means of surface preparation. Application The Contractor shall submit a method statement to the Employer's Representative and shall obtain the Employer's Representative's written approval before commencing impregnation operations. Impregnation of the face of a structural element shall be carried out in a single continuous operation for each application. Impregnation shall not be carried out within 7 days of the placing of the concrete, or 3 days after concrete repairs have been completed on a structural element. Particular attention is drawn to compliance with the requirements of surface condition. The material shall be applied by continuous spray technique giving saturation flooding, working from the lowest level upwards. Two applications shall be made, each at a coverage of 300 ml/m 2 with an interval between each of at least six hours. Impregnation shall not be carried out in the following conditions: (a) when the shade temperature is below 5 o C, (b) (c) when the temperature of the concrete surface is greater than 25 o C, when the wind speed is in excess of 8 km/hr unless the working area is fully encapsulated. Members shall be protected from rain and spray during application and for at least six hours after completion. Page 27 of 50

Disposal Disposal of impregnation material, any contaminated materials and protective sheeting or masking, shall be in strict accordance with the requirements of the Waste Disposal Authority. Whilst on site, all such materials must be retained in a safe and secure facility. The Contractor shall obtain all necessary certificates of approval for the disposal of the materials. Where required in the Contract, the Contractor shall carry out impregnation on trial panels 2m x 2m or equivalent area, one on a vertical and one on a horizontal surface. The Contractor shall then demonstrate on these panels, that the proposed method of working will meet the appropriate requirements of this Clause. The treatment applied shall be certified as effective for at least 15 years. Construction joints (3.11.1) 80.032 In addition to BS 5400: Part 7, clause 3.11.1, the following Construction joints shall not be formed in concrete completely or partly encasing a steel or concrete beam, except where shown on the Contract Drawings. The location of construction joints shall be selected to minimise plastic shrinkage and plastic settlement. Further to BS 5400: Part 7, clause 3.11.1, a fine water jet shall not be used where the spray is directed at, or may be blown towards, electrified line traction supply conductors. Formwork (3.11.2) 80.033 In addition to BS 5400: Part 7, clause 3.11.2, the following Formwork to produce the formed finishes in accordance with Clause 80.030 shall consist of: Class F1 closely jointed sawn boards, plywood sheet metal or other acceptable form material. Class F2 closely jointed prepared boards, smooth sanded plywood, sheet metal or other similar acceptable material arranged in a uniform pattern. Class F3 closely jointed prepared boards that have subsequently been machine sanded, plastic or vinyl faced plywood, polished sheet metal or other similar acceptable material, in panels not less than 2.4 metres by 1.2 metres. Page 28 of 50

Where a formwork lining is provided, the liner shall leave no stain on the concrete, and shall be joined and fixed to its backing such that no blemishes occur. With associated Method Statements, detailed drawings showing proposals for formwork shall be submitted by the Contractor for acceptance by the Employer s Representative, and shall indicate the materials to be used, method of construction, assembly and removal, method of fixing linings, position of construction joints, and all fixings that may affect the appearance of the finished concrete surface. Formwork to be re-used shall be thoroughly scraped, cleaned and made good as necessary to the acceptance of the Employer s Representative. Internal ties which would be required to be withdrawn through hardened concrete shall not be used where one of the faces is permanently exposed in the finished concrete. Internal ties left in the concrete shall be provided with a minimum concrete cover of 50 mm or the nominal cover to the adjacent reinforcement whichever is the greater. Additional requirements for controlled permeability formwork 80.034 Controlled permeability formwork (CPF) liner shall be used on exposed surfaces as shown on the Contract Drawings. The CPF liner shall have a current British Board of Agrément certificate and shall: (i) (ii) (iii) (iv) be non-compressible under pressure of the concrete within the formwork, have pore sizes which permit drainage of bleed water free from cement particles, be used once only and shall be used in accordance with the manufacturer s recommendations and technical guidelines, produce an even matt finish of uniform texture and finish, free from blow holes or other surface blemishes. Where CPF is used, the minimum striking times for formwork may be assessed in accordance with the recommendations of CIRIA Report No.136. Page 29 of 50

Transporting, placing and compacting of concrete (3.11.3) 80.035 Prior to placing concrete in any part of the Works, contingency plans shall be devised for adverse weather conditions. Local weather forecasts shall be obtained, and a check shall be carried out that the concrete mixes, logistical support and proposed methods of transporting, placing, compacting, finishing and curing the concrete are suitable for the forecast weather conditions. In addition to BS 5400: Part 7, clause 3.11.3, the following Concrete shall be transported and deposited in accordance with BS 8500-2:2002. Concrete, when deposited, shall have a temperature not below 5ºC, or greater than 30ºC. Precautions shall be taken during concreting on, over or adjacent to Network Rail premises, to prevent grout or concrete from coming into contact with the track, operational platforms, public highway or footpaths, adjacent property, the public and Network Rail s staff. Details of such precautions shall be included in the Contractor s method statement. Concreting operations shall not displace steel beams within the formwork. Concrete shall not be subject to a vertical drop in excess of 1.5 metres during discharging, unless a cohesive nonsegregating mix is used. Concrete to encase a steel beam shall be placed systematically on one side of the flange, and vibrated until the concrete appears on the other side of the bottom flange, at which point concrete may be added on that side of the beam. Particular care shall be taken to ensure that concrete completely fills the void between the flanges to encased steel beams. Where permanent formwork is incorporated in the Works, particular care shall be taken to ensure full compaction of the concrete is attained. Flexible waterstops shall not be displaced from their intended location during placing and compacting of the concrete and particular care shall be taken to ensure concrete adjacent to waterstops is completely compacted. Concrete to be placed underwater shall be placed using tremie pipes used in accordance with BS 8500-2:2002, clause 7.4.5.4.2. Page 30 of 50

No excess water shall be present on the top of the concrete surface after completion of compaction. Striking formwork (3.11.4) 80.036 Delete BS 5400: Part 7, clause 3.11.4.2, and the following Formwork supporting concrete in bending shall not be struck before the concrete compressive strength exceeds three times the values given in Appendix 80/7. This strength shall be confirmed by tests on concrete cubes or cylinders stored under conditions (agreed by the Employer s Representative) that simulate the site conditions. In the absence of test cubes or cylinders to determine the minimum period before striking formwork, for concrete made with Portland cement to BS EN 197-1:2000 or sulphate resisting cement to BS 4027 the minimum period shall not be less than the periods specified in BS 8110-1:1997, table 6.2. Formwork to precast concrete shall not be removed until the concrete has reached sufficient strength to allow the precast member to be handled without significant damage. Curing (3.11.5.1) 80.037 Delete BS 5400: Part 7, clause 3.11.5.1, and the following The method of curing shall prevent loss of moisture from the concrete. Immediately after compaction, the concrete shall be protected against the harmful effects of the weather, including rain, frost, rapid temperature changes, and from drying out. The protective measures shall continue for not less than the number of days specified in Table 80/2 or if the average surface temperature of the concrete falls below 10 C, for the equivalent maturity period specified in the Table 80/2. Page 31 of 50

TABLE 80/2: Minimum periods of normal curing for different types of concrete Conditions under which concrete is maturing Number of days (where the average surface temperature of the concrete exceeds 10 o C during the whole period) Equivalent Maturity (degree hours) ** 1. Hot weather or drying winds 2. Conditions not covered by 1 Other* SRPC PC Other* SRPC PC 7 4 3 3500 2000 1500 4 3 2 2000 1500 1000 Note Other* includes all permitted cements except Portland Cement (PC) and Sulphate-resisting Portland cement (SRPC) **calculated as the age of the concrete in hours multiplied by the number of degrees Celsius by which the average surface temperature of the concrete exceeds -10 o C Where not measured or calculated, the surface temperature shall be assumed to be equal to the temperature of the surrounding air. The mix shall be designed and other appropriate actions shall be taken to ensure that the temperature of the concrete mass shall not exceed 70 C. Details of all curing methods to be used, and where appropriate curing liquids, compounds, and membranes, shall be agreed by the Employer s Representative. Where a curing liquid, compound, or membrane is to be applied to surfaces to which silane surface impregnation is to be applied, in accordance with Clause 80.031, the curing liquid, compound, or membrane shall be a film type that fully degrades on exposure to ultra-violet light without leaving a residue that is detrimental to the surface impregnation of the concrete. In areas subject to significant shade the curing liquid, compound, or membrane shall be completely removable. Should the Contractor apply a curing liquid, compound or membrane to a surface that is to receive a waterproofing system in accordance with Sections 110-114: Waterproofing or to be painted in accordance with Sections 170-176: Protective Treatment the curing liquid, compound or membrane shall be completely removable or compatible with the appropriate system. Page 32 of 50

Accelerated curing (3.11.5.2) 80.038 In addition to BS 5400: Part 7, clause 3.11.5.2, the following When accelerated curing is used, the method of curing shall ensure that there are no deleterious effects on the strength or the durability of the concrete. Elevated-temperature curing as described below may be used only with Portland cement or sulphate-resisting Portland cement. (a) The formwork may be generally heated to no more than 20 o C prior to the placing of concrete. (b) Once the concrete is placed, it shall be left for 4 hours without additional heating. The concrete temperature can then be raised at a maximum rate of 10 o C per half hour. (c) (d) (e) The concrete temperature shall at no time exceed 70 o C. The rate of subsequent cooling shall not exceed the rate of heating. Cubes shall be manufactured and cured under identical conditions to those to which the concrete is subjected. The use of accelerated curing methods for concrete containing other types of cement or any admixture shall not be used. Additional requirements for mass concrete pours 80.039 Any concrete pour in which the minimum dimension exceeds 500 mm shall be considered to be a mass concrete pour in respect of heat of hydration. During mass concrete pours, measures in accordance with the Concrete Society Digest No. 2 shall be implemented to eliminate thermal cracking and plastic settlement. The rate and sequence of placing concrete shall prevent cold joints within the pour. Details of the methods to be adopted shall be agreed with the Employer s Representative. The limiting temperature differential shall not exceed the limits stated in Concrete Society Digest No. 2, table 6 appropriate to the aggregate type used. Page 33 of 50

Concrete Society Digest No 2. Table 6: Limiting temperature changes and differentials to avoid cracking Aggregate type Gravel Granite Limestone Lightweight Thermal expansion coefficient x 10-6 / o C 12.0 10.0 8.0 7.0 Tensile strain capacity -6 70 80 90 110 x10 Limiting temperature change in o C for different restraint factors: 1.0 0.75 0.50 0.25 7 10 15 29 10 13 20 40 16 19 32 64 20 26 39 78 Limiting temperature differential o C 20 28 39 55 Thermocouples accurate to a tolerance of ± 1 C shall be cast into mass concrete pours to measure temperature differentials in the concrete. The minimum number of thermocouples shall be two at the centre of the pour and one close to the face of each concrete surface. The number and location of the thermocouples, and method of protection during concrete placing, shall be agreed with the Employer s Representative. The frequency of temperature readings and the period for which such readings shall be required to be taken shall be agreed with the Employer s Representative. The results of such readings shall be correlated, and reported to the Employer s Representative. Adequate back up of essential Contractor s Equipment shall be available to ensure continuity of concrete placement during all stages of delivery, distribution, compaction and concrete finishing. The method of working for mass concrete pours shall include contingency plans for halting the concrete pour at any time and incorporating construction joints in accordance with Clause 80.032. Such contingency plans shall include: (i) (ii) (iii) the preferred location of construction joints, the method of forming joints, the assumptions made in the design given in Appendix 80/8. Page 34 of 50

Additional requirements for in situ concrete Precast concrete construction (3.11.8.1) 80.040 The concrete shall be constructed to the tolerances specified in BS 5606 table 1, unless amended by Appendix 80/9. 80.041 In addition to BS 5400: Part 7, clause 3.11.8.1, the following Members that are prestressed or post-tensioned shall be free of visible cracks following the application of the prestress. The actual camber of precast prestressed concrete units shall not exceed by more than 30% the predicted value stated on the Contract Drawings, when supported at the bearings and subject to self weight only. Where no value is stated the predicted value shall be derived from an elastic analysis based on the concrete section properties and effective modulus of elasticity at the actual age of measurement. The dimensional tolerances on the precast concrete units shall not exceed the tolerances stated in BS 8110-1:1997, clause 6.2.8.3 for length, cross section, straightness, squareness, twist and flatness, unless amended by Appendix 80/10. The dimensional tolerance on connecting bolts, bolt holes and projecting reinforcement shall not exceed the tolerances specified in BS 8110-1:1997, clause 6.2.8.6 Notwithstanding the above tolerances the Contractor shall remain responsible for the correct fit and compatibility of the precast concrete units within the Works. When two precast concrete beam units are match cast against one another, the previously cast unit shall be supported in such a way that on disassembly both units have compatible deflections in accordance with the design assumptions. The top surface of a precast concrete unit to receive in-situ concrete shall have a construction joint finish in accordance with Clause 80.032. (3.11.8.2) In addition to BS 5400: Part 7, clause 3.11.8.2 the following Precast prestressed concrete beams shall be supported at the bearings or at points as shown on the Contract Drawings. Should the method of handling and storage of the units require units to be in a stack several units high, packing pieces shall be vertically above each other. Page 35 of 50

(3.11.8.3) Further to BS 5400: Part 7, clause 3.11.8.3, precast concrete units shall only be lifted at the points shown on the Contract Drawings and shall be handled and placed without impact. (3.11.8.4) Further to BS 5400: Part 7, clause 3.11.8.4, the following Where appropriate, temporary supports or connections between units shall be provided to maintain the stability of the precast concrete units during erection and any subsequent concreting operations. Lifting equipment shall not be removed until such temporary supports or connections are effective. Such temporary supports or connections shall be removed when agreed by the Employer s Representative. Precast concrete units shall not be lifted and transported until the concrete has reached the compressive strength given in Appendix 80/11. Where precast units are laid side by side to form a bridge deck: (i) (ii) (iii) (iv) (v) (vi) the difference in soffit level shall not exceed 5 mm at any point between adjacent units, the difference in level of the top surfaces of abutting adjacent units to be waterproofed shall not exceed 5 mm, the width of the deck soffit shall be between +25 mm and -0 mm that is specified on the Contract Drawings, in adjacent spans the exterior beams shall be aligned to give visual continuity, the width of the gap between shear connected decks shall be ±5 mm that specified on the Contract Drawings provided that the gap between the shear connecting reinforcement links and the adjacent beam is not less than twice the nominal maximum aggregate size, the width of the gap between match cast precast concrete units shall not exceed 2 mm prior to transverse stressing, Page 36 of 50

(vii) (viii) the alignment of transverse holes shall permit the reinforcement or tendons to be placed without distortion, the alignment of shear connecting reinforcement links shall provide a minimum gap of twice the nominal maximum aggregate size between adjacent links. Grouting of prestressing tendons Where precast units are laid side by side to form a suspended floor, the variation in camber shall not exceed 6 mm. 80.042 Delete BS 5400: Part 7, clauses 3.12.1 to 3.12.8 inclusive and the following (3.12) The requirements for materials for grout including testing and full scale grouting trials, ducts, grouting equipment, method of mixing and injecting grout, and requirements for placing grout and grout properties shall comply with Concrete Society Technical Report No 47, section 3.3 and 4 as amended or qualified by this Clause. Grout for the protection of prestressing tendons shall be either common grout or special grout as defined in Concrete Society Technical Report No 47, and shall be selected by the Contractor to suit the chosen method of working. Where common grout is proposed to be used by the Contractor, unless agreed otherwise as a result of trials, the grout shall consist of cement complying with BS EN 197-1:2000, class 42.5N, admixtures in accordance with Concrete Society Technical Report No 47, section 3.3, clause 10 and Clause 80.009, and water in accordance with Clause 80.008. Full-scale trials of the grout mix and of the grouting operations shall be carried out, using the duct installation as shown on the Contract Drawings. The cross sections and longitudinal sections of the duct shall be exposed where shown on the Contract Drawings. The defaults given in section 3 of the Concrete Society Technical Report No 47 are required, unless otherwise amended in Appendix 80/12. Page 37 of 50

Reinforcement materials (4.1) 80.043 Further to BS 5400: Part 7, clause 4.1, all reinforcement steel shall be fabricated and supplied by a company holding a current UKCARES (UK Certification Authority for Reinforcing Steels) certificate of approval, or equivalent appropriate to the product standard. The Employer s Representative shall be provided with a copy of the UKCARES certificate of approval, and verification of the certificate and scope of approval obtained from: UK Cares Pembroke House 21 Pembroke Road Sevenoaks Kent TN13 1XR Tel: 01732 450000 Fax: 01732 455917 Email: general@ukcares.com The Employer s Representative shall be provided with a copy of the test certificates appropriate to each reinforcement type to be used. (4.1.1, 4.1.2) Delete BS 5400: Part 7, clauses 4.1.1 and 4.1.2 and the following Hot rolled and cold worked steel shall comply with BS 4449, but shall contain no flash welds. Epoxy coated reinforcement (designated E) shall comply with BS ISO 14654:1999 and BS ISO 14656. Stainless steel dowels and reinforcement shall be made from Type 304 S 31 or 316 S 33 and Grade 250 or 460 steel bars complying with BS 6744. (4.1.4) In addition to BS 5400: Part 7, clause 4.1.4, steel fabric shall be delivered either in flat mats or prebent. Bar schedule dimensions (4.2) 80.044 Further to BS 5400: Part 7, clause 4.2, the bar schedules are based on the dimensions of the concrete, and the nominal cover to the reinforcement. Reinforcement shall be cut and bent in accordance with BS 8666 and EN ISO 3766:2003 to the specified shape prior to fixing and placing. The Contractor shall remain responsible for the correct fit of the reinforcement, and provision of the specified cover. Page 38 of 50

If the method of construction necessitates rebending of reinforcement at the location of an original bend, the reinforcement bar shall be subject to the rebend test specified in BS 4449. Bars shall not be bent at a temperature lower than that at which the rebend test was carried out. Epoxy coated reinforcement shall not be reworked. Fixing (4.4) 80.045 Further to BS 5400: Part 7, clause 4.4, cover blocks shall be concrete of comparable strength, durability, and appearance as the surrounding concrete, with concrete mix proportions which match the adjacent concrete as closely as is practicable. In addition to BS 5400: Part 7, clause 4.4, the following Tying wire for reinforced concrete shall be 1.2 mm diameter stainless steel wire, except where epoxy coated reinforcement is used. Epoxy coated reinforcement shall be handled, stored, placed and fixed in accordance with BS ISO 14654:1999 clause 10. When the extent of damage to a coating exceeds 1% of the surface area on any metre length or the total damage area is in excess of 10 mm², whichever is the less, the bar shall not be incorporated in the Works. Reinforcement laps and joints (4.6) 80.046 Further to BS 5400: Part 7, clause 4.6, the following shall apply. Where specified, the coupling system for the reinforcement shall have a current British Board of Agrément Road and Bridges certificate, and the coupler shall comply with BS 8110: Part 1, clause 3.12.8.16.2. All parts of couplers used on coated epoxy reinforcement bars including sleeves, nuts, and bolts shall be coated with a compatible epoxy coating. The minimum lap for reinforcement shall be as specified on the Contract Drawings for bars, and for steel fabric and shall be not less than 250 mm with a minimum of two welded transverse bars. Page 39 of 50

Welding of reinforcement (4.7) 80.047 Delete BS 5400: Part 7, clause 4.7.1, and the following Welded reinforcement other than steel fabric reinforcement shall not be incorporated in the Works without the written agreement of the Employer s Representative. Should the Contractor propose to weld reinforcement, the Employer s Representative shall be provided with evidence that at each location, the fatigue life, durability and other properties of the structural member shall not be adversely affected. Welding of reinforcement shall not be carried out for reinforcement subject to variable loading, or where epoxy coated reinforcement is used. (4.7.3) Delete BS 5400: Part 7, clause 4.7.3, and the following Manual arc welding of reinforcement shall be carried out in accordance with BS 7123, and the recommendations of the reinforcement manufacturer. The Employer s Representative shall be provided with the following information for acceptance prior to welding commencing: (i) written welding procedures to BS 7123, clauses 11.9 and 12, approved by an independent testing authority, (ii) certificates for each welder to be provided by an independent testing authority appropriate to each weld type and procedure. Prestressing tendons materials (5.1) 80.048 Delete BS 5400: Part 7, clauses 5.1.1, 5.1.3 and 5.1.4, and the following Steel wire shall comply with BS 5896. Stress relieved seven-wire strand shall comply with BS 5896 or shall have properties that are not inferior. Prestressing anchorages for post-tensioning systems shall comply with BS EN 13391:2004. Page 40 of 50

Positioning of tendons, sheaths and ducts All prestressing steels shall be manufactured and supplied by a company holding a UKCARES (UK Certification Authority for Reinforcing Steels) certificate of approval, or equivalent. The Employer s Representative shall be provided with a copy of the UKCARES certificate of approval, and verification of the certificate and scope of approval (see Clause 80.043). Testing of materials shall be in accordance with BS 5896, and BS EN 13391:2004 and a copy of the test certificate appropriate to each prestressing steel and anchorage to be used shall be provided to the Employer s Representative. 80.049 Delete BS 5400: Part 7, clause 5.6, and BS 8110: Part 1, clause 8.6 (5.6) Where tendons debonded from the concrete are used, the debonding sheaths shall be acceptable to the Employer s Representative. The ends of the sheaths at the point of debonding shall be adequately taped to prevent the ingress of laitance or concrete. Tensioning the tendons (5.7) 80.050 In addition to BS 5400: Part 7, clause 5.7, the following The extensions and total forces, including allowance for losses shall be calculated before stressing commences. The extension of the tendons under the total forces shall be within 2% of the calculated extension. Forces in prestressing tendons shall not exceed 70% of their characteristic strength after anchoring. During stressing the value may exceed 70% with the agreement of the Employer s Representative but shall not exceed 80%. Page 41 of 50

Full records shall be kept of all tensioning operations whether pretensioned or post-tensioned, including measured extensions, load cell readings, and if applicable the draw-in at the anchorages. Copies of all records shall be provided to the Employer s Representative within 24 hours of completion of each tensioning operation. Protection of tendons (5.8) 80.051 Delete BS 5400: Part 7, clause 5.8 and the following shall apply. Prestressing tendons shall be protected by cement grout within a complete encapsulation resistant to the passage of air and water in accordance with Concrete Society Technical Report No 47, section 3.3, clause 3. Metal parts of anchorages shall be electrically bonded to the adjacent reinforcement at each end of the tendon. Electrical continuity of the structure over the length of the tendon shall be tested and proved. Supervision of prestressing operations 80.052 Prestressing and grouting operations shall be supervised by a competent member of the Contractor s personnel with appropriate knowledge, training and experience in carrying out similar operations. The Supervisor shall be present during all procedures and shall be responsible for all safety precautions relating to the operations. The appointment of the Supervisor shall be subject to the agreement of the Employer s Representative. All persons operating the stressing equipment shall have been trained in use of such equipment. For post-tensioning operations, the Supervisor and all operatives shall have been issued with statements of achievement in accordance with Concrete Society Technical Report No 47, annex B, as having attained the necessary level of skill and knowledge during training. Steel fibre for reinforced concrete generally 80.053 All steel fibre shall be manufactured and supplied by a company which has a quality system for product conformity approved in accordance with BS EN ISO 9001 by a body accredited by the United Kingdom Accreditation Service (UKAS) or equivalent. The Employer s Representative shall be provided with a copy of the certificate of product conformity and test certificates appropriate to each type of fibre to be used. Page 42 of 50

Steel fibre reinforcement shall be manufactured either from cold drawn wire or cold rolled low carbon sheet in accordance with the requirements of ASTM Standard A820-90, and shall have a deformed section. Steel fibres shall be supplied shrink wrapped or otherwise encapsulated to provide total weather protection until incorporation in the mix. Steel fibre for track slabs and hardstandings Steel fibre for sprayed concrete Concrete with steel fibres for track slabs and hardstandings 80.054 Steel fibres for track slabs and hardstandings shall be nominal single size between 40 and 60 mm long. The aspect ratio shall be between 60 and 75. 80.055 Steel fibres for sprayed concrete shall be nominal single size between 18 and 30 mm long. The aspect ratio shall be between 50 and 75. 80.056 Concrete containing steel fibre for track slabs and hardstandings shall be a designed mix for special structural concrete. The mix design shall be confirmed by trial mixes in accordance with Clause 80.018. The steel fibre content of the concrete shall be between 20 and 40 kg/m³. Concrete including steel fibre reinforcement shall be mixed to ensure fibre separation and a uniform distribution of fibres throughout the mix without balling or agglomeration. Compliance testing for steel fibre content of the concrete shall be carried out on a minimum of three batches by either: (i) (ii) weighing and crushing test cubes made in accordance with BS EN 12390-1:2000 and magnetically separating the steel fibres from the concrete particles, or washing out the steel fibres from a weighted sample of fresh concrete. The tolerance from the design requirement on the steel fibre content in the concrete established by compliance testing shall be ± 5%. Page 43 of 50

Synthetic fibre reinforced concrete 80.057 Synthetic fibre reinforcement shall be either 12 mm monofilament or 19 mm fibrillated polypropylene fibres with a British Board of Agrément certificate, and shall provide a reduction in plastic shrinkage crack area of not less than 85%. Synthetic fibre reinforcement shall be added to the mix at a dosage recommended by the manufacturer. Concrete including synthetic fibres shall be mixed to ensure fibre separation and a uniform distribution of the fibres throughout the concrete mix without balling or agglomeration. Compliance testing shall be carried out on samples of fresh concrete (each with a minimum weight of 5kg) taken from three batches in accordance with the European Specification for Sprayed Concrete clause 10.9, method C, published by the European Federation of National Association of Specialist Contractors and Material Suppliers for the Construction Industry. Requirements for sprayed concrete 80.058 Concrete for spraying shall be a designed mix for special structural concrete. In addition to the requirements of this Section of the Specification, sprayed concrete shall comply with and shall be applied and tested in accordance with the European Specification for Sprayed Concrete published by the European Federation of National Associations of Specialist Contractors and Material Suppliers for the Construction Industry, as amended by this Clause. (i) (ii) (iii) (iv) (v) Constituent materials shall be in accordance with the relevant Clauses in this Section of the Specification. Delete 5.5 of the EFNARC Specification, and Clause 80.009 (admixtures) Delete 6.2 of the EFNARC Specification, and Clause 80.013 (maximum chloride content) shall apply. Delete 6.3 of the EFNARC Specification, and Clause 80.015 (Control of ASR) In addition to 8.1 of the EFNARC Specification, the following shall apply: Page 44 of 50

Where water leakages are blocked by the use of accelerated cement paste-mortar, such cement paste-mortar shall not be considered to be part of the structural thickness. The requirements for preparation of concrete surfaces shall also apply to brickwork. (vi) In addition to 8.2 of the EFNARC Specification, the following shall apply: (a) (b) (c) (d) (e) the Employer s Representative shall be provided with certification to show that the foreman has a minimum of 5 years specialist spraying experience including two years as a nozzleman. The nozzlemen shall be competent and experienced in such work and shall have a working knowledge of sprayed concrete practice, sprayed concrete shall not be placed when the temperature of the substrate is less than 2 o C on a rising thermometer and 5 o C on a falling thermometer, for reinforced concrete the nozzle shall be held perpendicular to the application surface except when spraying around a reinforcing bar, when the nozzle may be held closer and at a slight angle in order to facilitate full and total encasement, rebound shall not be incorporated in the finished work, layer thickness shall be governed by the requirement that the material shall not slump or sag in such a manner that a break in the bond may be caused, Where the thickness required necessitates the application of more than one layer, subsequent layers shall not be placed until the preceding layer has attained adequate strength, when applying additional layers the reinforcement shall be cleaned of any previously deposited hardened material which might prevent bond or encasement., Page 45 of 50

(f) (g) construction joints should be tapered at approximately 30 and cut back square to the outer layer of reinforcement. Joints shall be thoroughly cleaned and dampened prior to the placement of further sprayed concrete, sprayed concrete shall be cured in accordance with Clause 80.037. Where the ambient temperature exceeds 25 C or in exposed conditions where air movement may cause a rapid drying of the concrete surface, as the spraying proceeds the work shall be immediately protected by wet hessian or a fog spray system. (vii) (viii) (ix) (x) (xi) The compressive strength grade of the sprayed concrete shall be as shown on the Contract Drawings. The flexural strength grade of the sprayed concrete shall be as shown on the Contract Drawings. Where sprayed concrete is specified to be watertight environmental class Highly Aggressive shall be used. Classes of control shall not apply. Preconstruction tests (in accordance with 11.2 of the EFNARC Specification) to determine the following shall be carried out as required by the Employer s Representative: Workability and pumpability Sprayability Slump Density Acceleration dosage Compression strength Flexural strength Residual strength value Toughness index Fibre content Bond (xii) Quality control shall be carried out at the frequency of one test for each 50 m³ unless directed otherwise in Appendix 8/13 to prove conformity of the following: Page 46 of 50

Compressive strength Flexural strength Residual strength value Energy absorption Bond Fibre content Thickness (xiii) (xiv) (xv) (xvi) The Employer s Representative shall be provided with a copy of the results of the preconstruction and quality control tests. Alignment control shall be carried out to ensure that the finished concrete surface does not reduce the existing structural clearances to the tracks except as shown on the Drawings. Such guides shall be agreed by the Employer s Representative. The sprayed concrete finish shall be as detailed in Appendix 80/14. All finished surfaces shall be uniform in texture and free from blemishes. The maximum tolerance on thickness on natural surfaces shall be between -0 mm and +15 mm. The maximum tolerance on thickness on tunnel surfaces shall be ±25 mm subject to paragraph (xiv) above. The maximum deviation in a 2.0 metre length shall be ±15 mm. Cover to reinforcement shall be as shown on the Contract Drawings and shall not be less than 25 mm. Floor construction 80.059 Floor toppings to in situ floors shall be deemed to be of monolithic construction when laid within three hours of the base concrete, or otherwise shall be deemed to be of separate construction. Base concrete, whether for monolithic or separate construction, shall be compacted before the topping concrete is placed. The surface shall be leveled to within 5 mm of the mean required level. Any chases required for conduits shall be formed in the base concrete. Page 47 of 50

Prior to application of the topping, the surface to the base concrete shall be thoroughly prepared as a construction joint in accordance with BS 5400: Part 7, clause 3.11.1, and Clause 80.032. The base concrete surface shall be clean and damp but not wet immediately before the topping is placed. Joints, size of concrete bay Vertical construction joints and the edges of concrete bays for the base concrete and topping concrete shall be coincident, whether for monolithic or separate construction. All construction joints shall be located over supporting beams of suspended floors. For monolithic construction, the area of concrete bay, bounded by the construction joints and the edges of the slab cast at one time, shall not exceed 15 m² for slabs between 100 mm and 150 mm total thickness or 30 m² for slabs over 150 mm total thickness. The maximum dimension of any bay shall not exceed 8.0 metres. For separate construction, the area of the bay defined as above shall not exceed 15 m² and the length of the bay shall not exceed 1½ times its width. Early age grinding 80.060 Early age grinding shall not be carried out until the concrete has hardened sufficiently to withstand grinding without aggregate being torn out from the surface under treatment. Fins, ribs or other projections shall be ground out to the mean required level to a tolerance within ±3 mm in a distance of 1.5 metres. Power floating 80.061 Where the finish is to be obtained by power floating the finish achieved shall be equivalent in all respects to that obtainable by hand trowelling with a steel trowel. Power floating shall not be considered to contribute in any way to compaction. It shall be applied after the concrete is placed and after such an interval that the concrete can be walked on and the power float operated without producing surface indentations greater than 3 mm. Page 48 of 50

REFERENCES This is a list of publications referred to within this Section of the Model Clauses. British Standards Part Applicable Edition Latest Amendment No 812 105.1 1989 812 106 1985 812 117 1988 812 120 1989 8773 877(*) 2 1973 4199 882 1992 13579 1370 1979 4416 4027 1996 4449 2005-5400 7 1978 5606 1990 9975 5896 1980 6699 1992 6744 2001 7123 1989 7128 8110 1 1997 17307 8500 1 2002 8500 2 2002 8666 2005 13111 EN 196 2 2005 EN 197 1 2000 EN 206 1 2000 15571 EN 450 1 2005 +A1:2007 EN 934 2 2001 EN 1008 -- 2002 EN 12350 1 2000 11081 EN 12350 2 2000 11080 EN 12350 3 2000 11079 EN 12350 4 2000 11082 EN 12350 5 2000 11078 EN 12350 6 2000 11077 EN 12350 7 2000 EN 12390 1 2000 15437 EN 12390 2 2000 14343 EN 12390 3 2002 EN 12390 7 2000 15440 EN 12390 8 2000 - EN 12620 2002 15333 EN 12878 2005 - EN 13055 1 2002 15339 EN 13391 2004 EN 14647 2005 16970 EN ISO 3766 2003 EN ISO 9001 2000 ISO 14654 1999 Page 49 of 50

ISO 14656 1999 (*) Withdrawn British Standards referred to in BS 5400 Part 7. Other publications Title Issue Date Concrete Society Digest No.2. 1985 Concrete Society Concrete Society CIRIA* Technical Report No 47. Durable bonded posttensioned concrete bridges. Technical Report No 30. Alkali-Silica Reaction: minimising the risk of damage to concrete - 3 rd edition. Report No 136. Formwork striking times criteria, prediction, and methods of assessment. 1996 1999 1995 EFNARC** European Specification for Sprayed Concrete. 1996 ASTM*** Standard A820: Specification for Steel Fibres for Fibres Reinforced Concrete. 1990 Highways Agency Manual of Contract Documents for Highway Works, Volume 1, Specification for Highway Works. 3/98 (Nov 2005 Amendments) *Constriction Industry Research and Information Association **European Federation of Specialist Contractors and Material Suppliers for the Construction Industry ***American society for Testing and Materials Model Clauses Title Section 85 Concrete for ancillary purposes 100 Bearings 110-114 Waterproofing 170-176 Protective Treatment Page 50 of 50