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1、BRITISH STANDARD BS 812-102: 1989 Testing aggregates Part 102: Methods for sampling UDC 625.07 + 691.22:620.113 BS 812-102:1989 This British Standard, having been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee, was published under the au
2、thority of the Board of BSI and comes into effect on 31 January 1990 BSI 02-2000 First published July 1984 New edition January 1990 The following BSI references relate to the work on this standard: Committee reference CAB/2 Draft for comment 89/10124 DC ISBN 0 580 17924 9 Committees responsible for
3、this British Standard The preparation of this British Standard was entrusted by the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee (CAB/-) to Technical Committee CAB/2, upon which the following bodies were represented: Aggregate Concrete Block Association Association of Co
4、nsulting Engineers Association of Consulting Scientists Association of Lightweight Aggregate Manufacturers Brick Development Association British Aggregate Construction Materials Industries British Cement Association British Ceramic Research Ltd. British Civil Engineering Test Equipment Manufacturers
5、 Association British Geological Sciences British Precast Concrete Federation Ltd. British Ready Mixed Concrete Association British Steel Industry Building Employers Confederation Calcium Silicate Brick Association Limited Chartered Institute of Building Concrete Society County Surveyors Society Depa
6、rtment of the Environment (Building Research Establishment) Department of the Environment (Property Services Agency) Department of Transport (Transport and Road Research Laboratory) Electricity Supply Industry in England and Wales Federation of Civil Engineering Contractors Institute of Concrete Tec
7、hnology Institution of Civil Engineers Institution of Highways and Transportation Institution of Structural Engineers Institution of Water and Environmental Management (IWEM) Mortar Producers Association Limited Sand and Gravel Association Limited Society of Chemical Industry Amendments issued since
8、 publication Amd. No.Date of issueComments BS 812-102:1989 BSI 02-2000i Contents Page Committees responsibleInside front cover Forewordii 0Introduction1 1Scope1 2Definitions1 3Principle1 4Apparatus1 5Procedure for sampling coarse, fine and all-in aggregates2 6Sample reduction3 7Nominal description3
9、8Despatch of samples4 9Certificate of sampling5 Appendix A Petrological description of natural aggregates6 Appendix B Recommended form of certificate of sampling8 Appendix C Description of particle shape and surface texture of aggregates9 Figure 1 Sampling scoops3 Figure 2 A suitable type of sample
10、divider (riffle-box)4 Figure 3 Typical particle shapes10 Table 1 Minimum number of sampling increments2 Table 2 Rock types commonly used for aggregates7 Table 3 Particle shape9 Table 4 Surface texture9 Publications referred toInside back cover BS 812-102:1989 ii BSI 02-2000 Foreword This Part of BS
11、812 has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee. This is a new edition of this Section of BS 812. This edition introduces technical changes to bring the standard up-to-date but it does not reflect a full review of the standar
12、d, which will be undertaken in due course. BS 812-102:19841) was a revision of clauses 3, 5 and 6 of BS 812-1:1975 and this edition re-introduces, in the form of an appendix, the description of particle shape and surface texture of aggregates previously contained therein. The remainder of the 1975 e
13、dition is being revised and as each of the tests, or collection of related tests is revised it is intended to issue it as a separate Part or Section of this standard. As part of the new approach to harmonization and standards in Europe, work on testing of aggregates will become part of the programme
14、 of work to be undertaken by CEN/TC 154, Aggregates. If the methods described in this standard are to be included in that programme then, under the CEN Regulations, they will become subject to standstill. The standstill is an obligation on the part of members of CEN/CENELEC not to publish during a g
15、iven period a new or revised national standard which is not completely in line with a European Standard (EN) or a Harmonized Document (HD) in existence or in preparation, or to take any other action which could prejudice the intended harmonization. The next edition of this standard could therefore b
16、e a dual British/European (EN) Standard. It is intended that other British Standards should call up BS 812 test methods as the basis of the compliance. Nevertheless, it is not intended that all aggregates should be subjected regularly to all the listed tests. Specifications in other standards should
17、 call up only relevant test methods. Some of the tests in other Parts of this standard are of limited application, and advice on the use of simpler tests is given, for example when they can be used for a preliminary sorting of aggregates to see whether more expensive testing is justified. Reference
18、should be made to BS 812-101 for general guidance on testing aggregates, precision of test methods and variance arising from sampling errors. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applic
19、ation. 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 and ii, pages 1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date
20、) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) Now withdrawn. BS 812-102:1989 BSI 02-20001 0 Introduction All the stages of sampling leading to the production of proper test portions require skill and care. Problems of several
21、kinds arise. a) Sampling may expose the operator to difficulty and possible danger. Due considerations should be given to the safety of the operator at all times. Sampling within the body of a vehicle or under chutes pose particular difficulties. b) Often it is not easy to discern a batch, and thus
22、specifications that rely on this standard should state the maximum quantity that a bulk sample should represent. c) Aggregates often segregate by size and, ideally, they should be sampled from large quantities during loading or unloading, but this is often impractical. The general principles of BS 5
23、309-1 and BS 5309-4 should be followed in drawing up sampling plans. The method set out in clause 5 should be used as the basis for tests for compliance with specifications for aggregates. Materials finer than 75 4m, used as fillers in bituminous mixtures, should be sampled in accordance with BS 455
24、0-1, using procedures appropriate to the type of delivery to produce a laboratory sample having a mass of at least 7 kg. The definitions of the several stages in the production of the test portions are given in clause 2. In some cases the bulk sample is inconveniently large to send for testing and h
25、as to be reduced. If not, it becomes the laboratory sample. At the laboratory, the laboratory sample is reduced to the test portions required. If adequate facilities exist at the point of taking the bulk sample, all necessary reduction to the stage of producing the test portions may be done before d
26、espatch to the laboratory. If several kinds of tests are to be done, an intermediate stage of reduction is necessary. In other cases, the test portion is reduced directly from the laboratory sample. It is again emphasized that care has to be taken to ensure that the test portions are representative
27、of the bulk sample. 1 Scope This Part of BS 812 describes methods for obtaining samples of aggregates of the quantity required for carrying out testing in accordance with other Parts of BS 812. The method to be used for recording the nominal description of materials sampled is also given. NOTEThe ti
28、tles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the definitions of petrological terms in BS 6100-5.2 apply (see also Appendix A) together with the following. 2.1 batch a definite quantity of some commo
29、dity manufactured or produced under conditions which are presumed uniform NOTEWith a continuous process the quantity produced during a specified period should be treated as a batch. 2.2 sampling increment a quantity of material taken at one time from a larger body of material NOTEWhen sampling aggre
30、gates, the material taken by a single operation of the scoop should be treated as a sampling increment. 2.3 bulk sample an aggregation of the sampling increments 2.4 laboratory sample a sample intended for laboratory inspection or testing 2.5 test portion the material used as a whole in testing or i
31、nspection NOTEWhen sampling a batch of aggregates, the aggregation of the sampling increments yields the bulk sample. If the bulk sample is of an appropriate size it is sent to the laboratory as a laboratory sample, otherwise it is reduced by a sample reduction process as described in clause 6 to th
32、e laboratory sample. At the laboratory, the laboratory sample is reduced by one or more reduction operations to the quantity required by a particular test method; the quantity of material produced at the final stage of sample reduction is referred to as the test portion. A particular test method may
33、 then require several specimens to be made from a test portion. 3 Principle Unless an explicit statement to the contrary is made in other Parts of this standard, the aim is to obtain a test portion that is representative of the average quality of the batch. 4 Apparatus 4.1 A small scoop, to hold a v
34、olume of at least 1 L (i.e. about 1.5 kg of aggregate of normal density). This scoop is used for sampling aggregates of nominal sizes less than 5 mm. BS 812-102:1989 2 BSI 02-2000 4.2 A large scoop, to hold a volume of at least 2 L (i.e. about 3 kg of aggregate of normal density). This scoop is used
35、 to sample any grading of aggregate, but is required particularly for aggregates of nominal sizes greater than 5 mm. NOTEA suitable scoop is shown in Figure 1. 4.3 Containers, clean and non-absorbent, such as buckets, for collecting the increments of a sample. 4.4 Containers, clean and impervious, s
36、uch as bags made of plastics at least 100 4m thick, for sending samples to laboratories. 4.5 A sample divider, appropriate to the maximum size to be handled, e.g. a riffle box such as that illustrated in Figure 2. Alternatively, a flat shovel and a clean flat and hard surface, e.g. a metal tray, for
37、 use in quartering. NOTEFor sampling in special circumstances other apparatus may be needed. For example, shovels, spades, picks, etc. may be needed to reach the material to be sampled. 5 Procedure for sampling coarse, fine and all-in aggregates The quantity of material to be represented by the bulk
38、 sample shall be clearly defined and the sample shall be taken by a responsible and experienced person. Obtain a bulk sample by collecting, in the clean containers, a sufficient number of increments (i.e. scoopfuls) to provide the required quantity of aggregate for all the tests subsequently to be m
39、ade. However the number of increments shall be not less than those given in Table 1. Take the increments from different parts of the batch in such a way as to represent the average quality. When replicate samples are required take each sample as a separate and independent operation. When sampling fr
40、om heaps of aggregate, take the required number of increments from positions evenly distributed over the whole surface of the heap. At the required spot for each increment remove as much surface material as necessary to expose aggregate at least 150 mm in from the surface. Take the increment by digg
41、ing the scoop into this exposed material. NOTE 1Aggregates that are badly segregated present problems of varying complexity and in many cases it is better to wait until they are moved. NOTE 2Sampling near ground level should be done with care to avoid contamination with, for example, residues of pre
42、vious materials. When sampling from material in motion, i.e. when it is being loaded or unloaded, calculate the sampling times to give the required number of sampling increments, ensuring that they are randomly distributed through the batch of aggregate. When sampling from a falling stream of aggreg
43、ate, take increments from the whole width of the stream. NOTE 3Mechanical samplers, manually or automatically operated, used for sampling from moving streams may be taken as being in accordance with this standard provided that each complete operation of the sampler produces an increment of at least
44、2 L of coarse or all-in aggregate or 1 L of fine aggregate. When sampling from conveyor belts, stop the conveyor at the appropriate time and take all the material from a fixed length of conveyor. CAUTION. Never sample manually from a moving conveyor. For all methods of sampling, combine all the incr
45、ements and either despatch the bulk sample or reduce it to a smaller representative sample, acceptable to the tester, by the procedure described in clause 6 and then despatch this smaller sample for testing. The sample despatched to the laboratory is the laboratory sample. On completion of the sampl
46、ing process, always make a visual check of the relation of the sample to the material in bulk. NOTE 4Whether the bulk is uniform or not, the sample should be seen to contain a similar range of sizes including the maximum and minimum. NOTE 5The procedure described in this clause is for obtaining a bu
47、lk sample representative of the batch sampled. When sampling is carried out to assess variability within a batch, a number of increments are taken from defined places in the batch and are not combined but tested separately. For routine testing quality control, simplified procedures may be used. Fewe
48、r increments may prove satisfactory for this purpose. Where it is necessary to determine the presence and quantity of an occasional contaminant, special measures may be necessary and reference should be made to the appropriate Part of this standard. These and other departures from the method should
49、be recorded on the certificate of sampling. Table 1 Minimum number of sampling increments Nominal size of aggregate Minimum number of sampling increments Approximate minimum mass for normal density aggregate Large scoopSmall scoop 28 mm and larger 5 mm to 28 mm 5 mm and smaller 20 10 10 half scoops 10 kg 50 25 10 BS 812-102:1989 BSI 02-20003 6 Sample reduction 6.1 General. It is sometimes necessary to reduce the mass of the bulk sample substantially. This shall be done in such a way as to preserve at each stage a representative part of the bulk sample. The