BS-5075-2-1982.pdf

BRITISH STANDARD BS 5075-2: 1982 (Reprinted, incorporating Amendments No. 1 and No. 2) Concrete admixtures Part 2: Specification for air-entraining admixtures UDC 666.972.168:693.542.4 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5075-2:1982 This British Standard, having been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee, was published under the authority of the Board of BSI and comes into effect on 26 February 1982 © BSI 12-1998 The following BSI references relate to the work on this standard: Committee reference CAB/3 Draft for comment 79/14045 DC ISBN 0 580 11739 1 Cooperating organizations The Cement, Gypsum, Aggregates and Quarry Products Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of Consulting EngineersInstitution of Civil Engineers* Association of County CouncilsInstitution of Highway Engineers Association of District CouncilsInstitution of Municipal Engineers Association of Metropolitan AuthoritiesInstitution of Public Health Engineers Autoclaved Aerated Concrete ProductsInstitution of Structural Engineers* AssociationInstitution of Water Engineers and British Precast Concrete Federation Ltd.*Scientists British Quarrying and Slag FederationNational Federation of Building Trades British Railways BoardEmployers* British Ready Mixed Concrete Association*Natural Environment Research Council British Steel Industry(Institute of Geological Sciences) Cement Admixtures Association*Royal Institute of British Architects Cement and Concrete Association*Royal Institution of Chartered Surveyors Cement Makers Federation*Sand and Ballast Hauliers and Allied Trades Chemical Industries AssociationAlliance Concrete Society Limited*Sand and Gravel Association Limited County Surveyors Society*Society of Chemical Industry* Department of the EnvironmentStone Federation (Building Research Establishment)* The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Department of the Environment (Housing and Construction) Department of the Environment (PSA)* Department of the Environment (Transport and Road Research Laboratory)Brick Development Association Department of Transport*British Ceramic Research Association Federation of Civil Engineering Electricity Supply Industry in England and Contractors*Wales Gypsum Products Development AssociationMortar Producers Association Ltd. Institute of QuarryingPlasterers Craft Guild Amendments issued since publication Amd. No.Date of issueComments 4184February 1983 4909October 1985Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5075-2:1982 © BSI 12-1998i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2References1 3Definitions1 4Sampling1 5Performance requirements1 6Admixture uniformity tests and requirements1 7Information to be provided by the manufacturer1 8Manufacturers compliance certificate3 9Manufacturers storage certificate3 10Marking3 Appendix A Preparation of concrete for admixture acceptance tests4 Appendix B Admixture acceptance tests on the control mix and test mix concretes5 Appendix C Test for resistance to freezing and thawing6 Appendix D Notes on the use of air-entraining admixtures8 Table 1 Performance requirements and tests2 Table 2 Admixture uniformity test requirements2 Table 3 Fine aggregate grading limits4 Table 4 Approximate quantities of concrete required for each admixture acceptance test on a batch5 Standards publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5075-2:1982 ii © BSI 12-1998 Foreword This Part of this British Standard has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee and is based on an initial draft provided by the Cement Admixtures Association. This Part of this standard incorporates such recommendations of other organizations as the Technical Committee felt were appropriate, and is based on the results of cooperative tests carried out in accordance with drafts of this Part. This Part of this standard is concerned only with admixtures whose sole function is to entrain air in concrete. Air-entraining admixtures with additional properties, such as accelerating or retarding effects, have not been included because of the wide variation in the quantity of air-entraining admixture required to entrain a given quantity of air according to the actual circumstances prevailing, and consequent varying magnitude of such supplementary effects in practice. Accelerating admixtures, retarding admixtures and water-reducing admixtures are covered by Part 1 of this standard and mortar plasticizers are covered by BS 4887. This Part of this standard specifies acceptance tests which demonstrate the ability of a particular admixture formulation to meet stipulated performance requirements in a specified concrete, and admixture uniformity tests which demonstrate that a particular consignment is similar to material that has previously been submitted to the acceptance tests. These acceptance tests include a selection of tests at one workability on a single control concrete without any admixture and on a similar test concrete of the same cement content and workability containing sufficient admixture to produce a stipulated air content of 5.0 ± 0.5 %. The effects of air-entraining admixtures on properties other than those covered, or on special concretes, are not specified and these should be the subject of advice from the admixture manufacturer. In the acceptance tests, particular attention has been given to the use of test methods already covered in BS 1881 and BS 4551. Furthermore, the principle has been followed of having test and control mix concretes with the same cement content at nominally equal workabilities, as determined by compacting factor tests. However, workability can vary rapidly during the early stages after completion of mixing of concretes, and consequently a delay of 10 min to 15 min has been introduced into the procedure for compacting factor determination, so as to avoid this period of high variability. Control and consistency of the air-entraining performance of the admixture is covered by the requirement specified for repeatability of air content. The stability of the entrained air during the transition from fresh to hardened concrete is ensured by the saturated density requirement which also checks that the test mix concrete cubes and prisms have similar air contents. A stiffening-time test, which is carried out on mortar sieved from concrete, is included to establish that the air-entraining admixture does not significantly affect the setting of concrete. The resistances to penetration of 0.5 N/mm2 and 3.5 N/mm2 correspond approximately to the extreme limit for placing and compacting concrete and the time available for the avoidance of cold joints. This Part of this standard also deals with the effects of entrained air on compressive strength and resistance to the action of repeated freezing and thawing under wet conditions. The Technical Committee gave consideration to other possible tests for characterizing the quality of the air entrained in concrete by use of the admixture, such as change in air content on prolonged mixing, loss of entrained air on standing or on vibration, and estimation of the size and distribution of air voids by microscopical examination of polished concrete sections, but these have not been included because of difficulties of standardization and/or of interpreting the results. The direct freezing and thawing test adopted in this Part has been kept as simple as possible to avoid difficulties in its implementation, but it is believed that the test will provide adequate information on admixture performance with respect to the potential frost resistance of the air-entrained concrete. Of the various methods available for assessing the effects of repeated freezing and thawing on concrete, the change in length method was found in cooperative testing to be the most sensitive and convenient method to use and accordingly this method has been specified in this Part. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5075-2:1982 © BSI 12-1998 iii The admixture uniformity tests include determination of dry material content, ash content and chloride ion content for all admixtures, and relative density for liquid admixtures. Although air-entraining admixtures are not normally expected to contain significant quantities of chloride, this Part of this standard requires, as a general safeguard, that the chloride content of all admixtures be declared. This declaration enables the purchaser or user to be fully aware of the amount of chloride that will be introduced into concrete by the use of any particular admixture and, if necessary, to take appropriate precautions. The admixture dosage is dependent on many factors which govern the performance of an air-entraining admixture in achieving a specified air content. This leads to considerable variation in dosage, comparing one site with another, and it is unlikely that the dosage used in the admixture acceptance tests complying with this Part of this standard will be the optimum amount for use in a particular situation. Site trials are required, and some guidance on this topic as well as on the general use of air-entraining admixtures is given in appendix D. Certification. Attention is drawn to the certification facilities described on the inside back cover of this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 16:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5075-2:1982 © BSI 12-19981 1 Scope This Part of this British Standard specifies the requirements and methods of test for determining the suitability of materials used to entrain a controlled amount of air in concrete, for the purpose of improving its resistance to freezing and thawing and/or modifying its workability. 2 References The titles of the standards publications referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of this Part of this British Standard the definitions given in BS 2787, together with the following, apply. air-entraining admixture an admixture that causes a controlled and stable quantity of air to be incorporated during the mixing of concrete, without significantly affecting the setting of the concrete NOTEThis entrained air reduces the water requirement of concrete (or alternatively increases the workability of fresh concrete at constant water/cement ratio) and provides hardened concrete of increased resistance to freezing and thawing, without lowering the strength beyond certain limits. 4 Sampling An admixture to be tested in accordance with the requirements of this Part of this standard shall be sampled by the appropriate method described in appendix A of BS 5075-1:1982. 5 Performance requirements Admixtures shall comply with the performance requirements detailed in Table 1. For the purposes of acceptance testing, a representative sample of admixture, as defined in the appropriate subclause in appendix A of BS 5075-1:1982, shall be subjected to the tests listed in Table 1 and shall comply with the relevant requirements specified therein. Each test mix containing the admixture shall be compared with a control mix made on the same day under the same conditions and the average result obtained from two such comparisons shall be taken to assess compliance with the requirements for stiffening time, saturated density and compressive strength given in Table 1. Consignments of this admixture which have the same description, given as in 7.3 a) and b), need not be tested individually for acceptance. If any characteristic of the admixture given in 7.3 a) and b) is changed, new acceptance tests shall be carried out and the designation as given in clause10 b) shall be changed. NOTE 1Although the purpose of the tests is to verify compliance with the specified requirements, the results will also serve to demonstrate the effect of the admixture on certain properties of the concrete. NOTE 2For the purposes of acceptance testing, the manufacturer1) or his agent may be required by the purchaser to demonstrate compliance with the test requirements. The manufacturer is responsible thereafter for ensuring, by his control of production, that consignments of admixture maintain, on delivery, the performance of the sample originally tested for acceptance. 6 Admixture uniformity tests and requirements Any batch of admixture shall have the same composition, given as in 7.3 b), as that of the admixture tested for acceptance. To check this uniformity of composition, a sample of the batch taken in accordance with appendix A of BS 5075-1:1982 shall be tested in accordance with appendices D and E of BS 5075-1:1982 and it shall satisfy the requirements given in Table 2. 7 Information to be provided by the manufacturer 7.1 Information concerning the admixture. The following information shall be provided by the manufacturer in a printed form. a) The name, trade mark or other means of identification of the manufacturer. b) The trade designation of the product, i.e. brand name, reference number and/or letter. c) The description of the material, i.e. air-entraining admixture. 7.2 Information concerning the admixture acceptance tests. The following information shall be provided by the manufacturer in a printed form if requested. a) The name and location of the test laboratory where admixture acceptance and uniformity tests were made and the date of testing. b) The sources of the cement (works of manufacture) and aggregates (quarry or pit, or, for material dredged from seas, estuaries or rivers, the locality). c) The quantity of admixture used in the test mix concretes. 1) The term “manufacturer” throughout th