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1、BRITISH STANDARD BS 4887-2: 1987 Mortar admixtures Part 2: Specification for set retarding admixtures UDC 666.971.165 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4887-2:1987 This British Standard, having been prepared under the direct
2、ion 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 29 May 1987 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference CAB/3 Draft for comment 86/11852
3、 DC ISBN 0 580 15954 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Cement, Gypsum, Aggregates and Quarry Products Standards Committee (CAB/-) to Technical Committee CAB/3 upon which the following bodies were represented: Brick Develo
4、pment Association British Aggregate Construction Materials Industries British Ceramic Research Limited British Precast Concrete Federation British Ready Mixed Concrete Association Building Employers Confederation Cement Admixtures Association Cement and Concrete Association Cement Makers Federation
5、Concrete Society County Surveyors Society Department of the Environment (Building Research Establishment) Department of the Environment (Property Services Agency) Department of Transport (Highways) Electricity Supply Industry in England and Wales Federation of Civil Engineering Contractors Instituti
6、on of Civil Engineers Institution of Structural Engineers Mortar Producers Association Plasterers Craft Guild Society of Chemical Industry Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Co
7、py, (c) BSI BS 4887-2:1987 BSI 03-1999i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Definitions1 3Performance requirements1 4Uniformity requirements1 5Information to be provided2 6Marking3 Appendix A Methods of sampling admixtures4 Appendix B Preparation of mortars for
8、 acceptance tests4 Appendix C Acceptance tests on control mix and test mix mortars6 Table 1 Performance requirements and acceptance tests1 Table 2 Uniformity requirements and tests2 Table 3 Grading of sand5 Table 4 Composition of mortars5 Table 5 Mixing procedure6 Publications referred toInside back
9、 cover Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4887-2:1987 ii BSI 03-1999 Foreword This Part of BS 4887 has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee. BS 4887-1 spe
10、cifies requirements for air-entraining (plasticizing) mortar admixtures. It is intended to prepare, under the general title “Mortar admixtures”, further Parts to cover other admixtures now in use in building mortars. This Part specifies the requirements for set retarding admixtures for use, both wit
11、h and without lime, in mortars for bedding masonry units, for plastering and for rendering. Requirements for set retarding admixtures for use in screeding mortars are specified in BS 5075-1. Mortar admixtures are used in building mortars in small quantities to improve specific properties of the mort
12、ar. Those covered by this Part of BS 4887 are designed to extend the working life of fresh mortar. They may also affect other properties so it is necessary to demonstrate that these effects are not adverse. The test methods included cover those properties of mortars likely to be important when they
13、are used in bedding masonry units, plastering and rendering. All test methods have been taken from BS 4551; details of procedures are given in Appendix B and Appendix C. The set retarding admixture is tested in a mortar containing entrained air. The air-entraining admixture used to produce this is r
14、equired to comply with BS 4887-1. To reduce the effects of different raw materials on test results, most test methods use a control mix and a mix containing the admixture. In this Part of BS 4887, only mortar complying with designation iii of BS 4721 has been included but both lime and non-lime mort
15、ar types are required to be tested to qualify for universal use. It is known that the properties of different constituent materials as well as the use of different mortar mixes can change the required dosage of an admixture. It is important that the user checks the properties of the mixes to be used
16、 on site. 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
17、comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, 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: s
18、heffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4887-2:1987 BSI 03-19991 1 Scope This Part of BS 4887 specifies the requirements for performance and uniformity and methods of test for set retarding mortar admixtures added to extend the working life of bu
19、ilding mortars. These are prepared both with and without lime for use in bedding masonry units, plastering and rendering but not normally for use in screeding. NOTEThe titles of the publications referred to in this Part of BS 4887 are listed on the inside back cover. 2 Definitions For the purposes o
20、f this Part of BS 4887 the definitions given in BS 4049 and BS 6100-6.4 apply. 3 Performance requirements The admixture shall enable a test mortar to comply with the performance requirements given in Table 1 when test mixes of the mortar, containing representative samples of the admixture taken as d
21、escribed in Appendix A, are prepared as described in Appendix B and subjected to the acceptance tests described in Appendix C. A test mix mortar of standard consistence, i.e. complying with the requirement given in Table 1 when tested as described in C.2, containing the admixture under test shall be
22、 compared with a control mix mortar of standard consistence made on the same day under the same conditions and the mean results obtained from two comparisons, not necessarily on the same day, shall be used to assess compliance with the performance requirements for air content and 28 day compressive
23、strength. Part of the text mix mortar shall be stored for 28 h and then tested for consistence, air content and specimens made for testing 28 day compressive strength. The sample to be used to test resistance to penetration shall be stored for a further 24 h and then checked to determine whether the
24、 mortar has set. Batches of the admixture that have the same formulation, as described in 5.1 c) and k) need not be tested individually for acceptance if they have been shown by the uniformity tests in clause 4 to have the same composition as that of the admixture tested for acceptance and complying
25、 with the performance requirements. 4 Uniformity requirements Any batch of admixture shall have the same composition, as given in 5.1 k), as that of the admixture tested for acceptance. To check this uniformity of composition, a sample of the batch, taken as described in Appendix A, shall be tested
26、in accordance with Appendixes D and E of BS 5075-1:1982 and shall comply with the requirements given in Table 2. Table 1 Performance requirements and acceptance tests CharacteristicTest referenceRequirement (mean of two batches) Consistence after: a) standard mixing b) 28 h standing C.2 C.5 Mean dro
27、pping ball penetration of 10 0.5 mm Not more than 4.0 mm less than the value after standard mixing Air content after: a) standard mixing b) 28 h standing C.3 C.7 14.0 % to 20.0 % Not less than 70 % of the value after standard mixing Resistance to penetration after: 52 h standingC.6 Not less than 5 N
28、/mm2 28 day compressive strength on cubes made after: a) standard mixing b) 28 h standing C.4 C.8 Not less than that of the control mix Not less than that of the control mix Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4887-2:1987 2 BS
29、I 03-1999 Table 2 Uniformity requirements and tests 5 Information to be provided 5.1 Test information The following test information shall be available in writing1). a) The name, trade mark or other means of identification of the manufacturer. b) The trade designation of the product, i.e. brand name
30、, reference number and/or letter. c) The description of the material, i.e. set retarding mortar admixture, its physical state (liquid or solid), its colour and the generic type of its main active constituent(s). d) The name and location of the test laboratory where acceptance and uniformity tests we
31、re made and the date of testing. e) The sources of the cement, lime, sand and air-entraining admixture used in the tests. f) The mass of air-entraining admixture and of the admixture under test, both calculated on the mass of cement, used in the test mix mortar. g) The consistence of each control an
32、d test mix mortar and the mean values of each pair. h) The air content of each control and test mix mortar after standard mixing and, for the test mix mortar, after 28 h standing and the mean values of each pair. i) The resistance to penetration of each test mix mortar after 52 h and the mean values
33、 of each pair. j) The compressive strengths of the individual mortar cubes for the control and test mix mortars made after standard mixing and, for the test mix mortar, after 28 h standing and the mean compressive strengths at age 28 days. k) The composition, as follows: 1) the dry material content;
34、 2) the ash content; 3) the relative density of liquid admixture; 4) the chloride ion content, expressed as a percentage by mass of total admixture. 5.2 General information The following general information shall be available in writing1). a) The name, trade mark or other means of identification of
35、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. set retarding mortar admixture, its physical state (liquid or solid), its colour and the generic type of its main active constituent(s). d) Packaging,
36、recommended storage conditions, maximum storage time before use and special precautions at extremes of temperature, including instructions regarding liquids which have become frozen. Where any special requirements on storage life apply, they shall be stated. NOTEA certificate confirming that the sto
37、rage recommendations have been followed should be provided by the manufacturer. e) Instructions for use and any necessary safety precautions, e.g. if caustic, toxic or corrosive. f) Any known incompatibility with other admixtures or with certain types of cements, etc. g) The manufacturers recommende
38、d dosage or dosages. h) Effects of underdosage and overdosage. CharacteristicTest referenceRequirement Dry material contentD.1 of BS 5075-1:1982a) For liquid admixtures: to be within 3 % (m/m) of the value stated by the manufacturera b) For solid admixtures: to be within 5 % (m/m) of the value state
39、d by the manufacturer Ash contentbD.2 of BS 5075-1:1982To be within 1.0 % (m/m) of the value stated by the manufacturer Relative densityD.3 of BS 5075-1:1982For liquid admixtures: to be within 0.02 of the value stated by the manufacturer Chloride ion contentAppendix E of BS 5075-1:1982 To be within
40、5 % of the value stated by the manufacturer or within 0.2 % (m/m), whichever is the greater a The term manufacturer throughout this standard includes the supplier where appropriate. b Not applicable to admixtures containing more than 1 % (m/m) of chloride ion. 1) Information is normally provided by
41、the manufacturer but may be made available by a supplier after repackaging bulk material. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4887-2:1987 BSI 03-19993 6 Marking When admixtures are supplied in containers they shall be clearly
42、marked for the purposes of identification and indication of compliance with the following information. When the material is supplied in bulk at the point of delivery, the same information shall be provided in writing at the time of delivery. a) The name, trade mark or other means of identification o
43、f 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. set retarding mortar admixture. d) The chloride ion content, expressed as a percentage by mass of total admixture. e) A summary of storage requiremen
44、ts including any special requirement on storage life, as indicated in 5.2 d) which shall be clearly marked, e.g.: “This admixture shall not be taken to comply with the requirements of BS 4887-2:1987 after (date).” f) Instructions for use and any necessary safety precautions, e.g. if caustic, toxic o
45、r corrosive. g) The manufacturers recommended dosage or dosages. h) The number and date of this Part of this British Standard, i.e. BS 4887-2:19872). 2) Marking BS 4887-2:1987 on or in relation to a product is a claim by the manufacturer that the product has been manufactured to the requirements of
46、the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification should be addressed to the appropriate certification body. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:10:36 GMT+00:00 2006, Un
47、controlled Copy, (c) BSI BS 4887-2:1987 4 BSI 03-1999 Appendix A Methods of sampling admixtures A.1 General Take samples of admixtures in accordance with the appropriate method given in A.2 to A.5. In all steps of the sampling procedure minimize the exposure of the material to the atmosphere to avoi
48、d appreciable absorption of moisture or carbon dioxide, or the evaporation of moisture. A.2 Sampling of powdered materials from packages Each sample shall represent not more than 1 t of solid admixture. Sample six packages or 1 % of the number of packages, whichever is the greater, or, where the tot
49、al number of packages does not exceed six, all the packages. Ensure that the packages sampled are evenly distributed throughout the consignment. Take a sub-sample from each of the selected sample packages by one or more of the following procedures, as appropriate. a) Where packages contain 500 g or less, take the whole of the contents of a package. b) Where packages contain more than 500 g, use either of the following methods. NOTEThe method given in 1) is the preferred method but if a sampling tube is not available use the method given in 2). 1) Insert a
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