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1、BRITISH STANDARD BS 812-103.1: 1985 Reprinted, incorporating Amendment No. 1 Testing aggregates Part 103: Methods for determination of particle size distribution Section 103.1 Sieve tests UDC 625.07 + 691.22:620.168.36 BS 812-103.1:1985 This British Standard, having been prepared under the direction
2、 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 30 August 1985 BSI 12-1998 The following BSI references relate to the work on this standard: Committee reference CAB/2 Draft for comment 84/10136
3、 DC ISBN 0 580 14474 7 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/2, upon which the following bodies were represented: Aggregate Con
4、crete Block Association Association of Consulting Engineers Association of Consulting Scientists Association of Lightweight Aggregate Manufacturers Brick Development Association British Aggregate Construction Materials Industries British Ceramic Research Association British Civil Engineering Test Eq
5、uipment Manufacturers Association British Precast Concrete Federation Ltd. British Ready Mixed Concrete Association Calcium Silicate Brick Association Limited Cement and Concrete Association Cement Makers Federation Chartered Institute of Building Concrete Society County Surveyors Society Department
6、 of the Environment (Building Research Establishment) Department of the Environment (Property Services Agency) Department of the Environment (Transport and Road Research Laboratory) Department of Transport (Highways) Electricity Supply Industry in England and Wales Federation of Civil Engineering Co
7、ntractors Greater London Council Institute of Concrete Technology Institution of Civil Engineers Institution of Highways and Transportation Institution of Public Health Engineers Institution of Structural Engineers Institution of Water Engineers and Scientists Mortar Producers Association Ltd. Natio
8、nal Federation of Terrazzo (Mosaic Specialists) Natural Environment Research Council (Institute of Geological Science) Royal Institute of British Architects Sand and Gravel Association Limited Society of Chemical Industry Amendments issued since publication Amd. No.DateComments 6003June 1989Indicate
9、d by a sideline in the margin BS 812-103.1:1985 BSI 12-1998i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Definitions1 3Principle1 4Sampling1 5Apparatus1 6Preparation of test portion1 7Procedure2 8Calculation and expression of results3 9Precision3 10Test report3 Table 1
10、 Particulars of sieves for sieve analysis1 Table 2 Minimum mass of test portion for sieve analysis2 Table 3 Maximum mass to be retained at the completion of sieving4 Table 4 Precision data for determination of particle size distribution4 Figure 1 Chart for recording sieve analysis results5 Appendix
11、A Preparation and cleaning of test sieves6 Appendix B Checking of test sieves6 Publications referred toInside back cover BS 812-103.1:1985 ii BSI 12-1998 Foreword This section of BS 812, prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee, is a revi
12、sion of 7.1 of BS 812-1:1975, which is withdrawn by amendment. The remaining sections of BS 812-1 and BS 812-2, 3 and 4 are also 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. It is intend
13、ed that other British Standards should call up BS 812 test methods as the basis of compliance. Nevertheless, it is not intended that all aggregates should be subjected regularly to all the listed tests. Requirements in other British Standard specifications will refer only to the relevant test method
14、s. Some of the tests in other Parts of BS 812 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. Removal of fine material by decantation, described
15、 as the modified method in the BS 812-1, has been made the preferred method in this revision to ensure reliable testing of aggregate containing fine material that may cause agglomeration of particles. In this revision the masses retained at the completion of sieving have been rationalized. Reference
16、 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 appli
17、cation. 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 6, an inside back cover and a back cover. This standard has been updated (see copyright date
18、) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. BS 812-103.1:1985 BSI 12-19981 1 Scope This Section of BS 812 describes two methods for the determination of the particle size distribution of samples of aggregates and fillers by sie
19、ving. NOTE 1For sampling and testing lightweight aggregates for concrete see BS 3681. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Section of BS 812 the definitions given in BS 812-101 and BS 812-102 app
20、ly. 3 Principle 3.1 Washing and sieving This is the preferred method (see 7.2) for aggregates which may contain clay or other materials likely to cause agglomeration of particles. It involves preliminary separation by washing through a fine sieve before determining particle size distribution by dry
21、sieving. 3.2 Dry sieving This is an alternative method (see 7.3) which may be used for coarse and fine aggregates free from particles which cause agglomeration. NOTE 1Dry sieving gives inaccurate results for aggregates containing clay but is quicker and less laborious to carry out than washing and s
22、ieving. NOTE 2It is not possible to specify accurately the amount of clay or other materials which will make the method given in 7.3 inappropriate and unless it can be demonstrated (e.g. by previous experience) that that method gives accurate results, it is recommended that the method described in 7
23、.2 should always be used. Because of this some materials specifications may call for washing and sieving to be followed at all times. 4 Sampling The sample used for the test (the laboratory sample) shall be taken in accordance with the procedures described in clause 5 of BS 812-102:1984. 5 Apparatus
24、 5.1 A sample divider, of size appropriate to the maximum particle size to be handled or alternatively a flat shovel and a clean, flat, hard horizontal surface, e.g. a metal tray for use in quartering. NOTEA suitable divider is the riffle box illustrated in BS 812-102. 5.2 A ventilated oven, thermos
25、tatically controlled to maintain a temperature of 105 5 C. 5.3 A balance, or balances, of suitable capacity accurate to 0.1 % of the mass of the test portion. NOTEIn general, two balances, one of approximately 5 kg capacity accurate to 1 g and the other of approximately 500 g capacity accurate to 0.
26、1 g, will suffice. If aggregate of larger than 28 mm nominal size is to be tested a balance of 50 kg capacity accurate to 10 g will also be required. 5.4 Test sieves and nesting guard sieve, of the sizes and apertures appropriate to the specification of the material being tested, complying with BS 4
27、10 and with the appropriate sizes of lid(s) and receivers. NOTE 1A set of sieves of the sizes and apertures given in Table 1 will cover most applications of the method. NOTE 2Some advice on cleaning and checking sieves is given in appendices A and B. Table 1 Particulars of sieves for sieve analysis
28、5.5 A mechanical sieve shaker (optional). 5.6 Trays, that can be heated in the ventilated oven (5.2) without damage or change in mass. 5.7 Containers, of a size sufficient to contain the test portion plus five times its volume of water (for washing and sieving method only). 6 Preparation of test por
29、tion Reduce the sample in accordance with the procedures described in clause 6 of BS 812-102:1984 to produce the required number of test portions each of which complies with the minimum mass given in Table 2. Dry the test portions by heating at a temperature of 105 5 C to achieve a dry mass which is
30、 constant to within 0.1 %. Allow to cool, weigh and record as M1. Nominal aperture sizes Square hole perforated plate, 450 mm or 300 mm diameter Wire cloth, 300 mm or 200 mm diameter mmmm 75.03.35 63.02.36 50.01.70 37.51.18 28.0 20.0 m 14.0850 10.0600 6.30425 5.00300 212 150 75a a For some applicati
31、ons, 63 m is appropriate. BS 812-103.1:1985 2 BSI 12-1998 Table 2 Minimum mass of test portion for sieve analysis 7 Procedure 7.1 General 7.1.1 For some materials, e.g. all in aggregates or hoggin, the particle size distribution may result in excess mass on one or more sieves particularly on the fin
32、er sizes. Therefore, if it is not possible to include extra sieves of appropriate intermediate size to reduce the loading, adopt one of the following procedures. a) Subdivide the test portion into two or more sub-portions. Determine the particle size distribution for each portion and combine the res
33、ults for the purpose of reporting. b) Separate the test portion on an appropriate sieve, e.g. 20 mm or 5 mm. Weigh the retained and passing fractions to determine the proportion of each present. Determine the particle size distribution of each fraction separately, reducing where necessary by quarter
34、ing or by means of a sample divider (5.1) as described in clause 6 of BS 812-102:1984. Calculate the particle size distribution of the original sample by combining the results for each fraction in the proportions present. 7.1.2 When special procedures for fillers are required to measure the amount f
35、iner than 75 m, carry these out either in accordance with 7.2 of BS 812-1:1975 or BS 812-1041). 7.2 Washing and sieving method 7.2.1 Preliminary separation 7.2.1.1 Wet both sides of a 75 m test sieve (5.4), reserved for use in this test only, and fit a nesting guard sieve (e.g. 1.18 mm) on top. Moun
36、t the sieves in such a way that the suspension passing the test sieve can be run to waste or, when required, collected in a suitable vessel. 7.2.1.2 Place the weighed oven dried test portion in a container (5.7) and add sufficient water to half fill the container. Agitate the contents so that partic
37、les smaller than 75 m are completely separated from coarser particles. NOTESoaking or continued agitation or, in the case of large particles, brushing may be required to achieve complete separation. 7.2.1.3 Pour the suspension of fine solids on to the guarded 75 m test sieve. NOTEThe suspension pass
38、ing the test sieve may be run to waste unless it is required for other purposes. 7.2.1.4 Continue washing the coarse residue until the water passing the test sieve is clear (see note 2) and then wash all the residues from the container and sieve(s) into the tray (5.6). Remove excess free water by ca
39、reful decantation through the test sieve, avoiding transfer of solids (see note 2) and dry the residue in the oven (5.2) at 105 5 C until constant mass is achieved. Cool, weigh and record as M2. NOTE 1Avoid excess water flows which may damage or flood the sieves. NOTE 2If some transfer of solids doe
40、s occur wash them back into the tray and repeat the operation. NOTE 3Fine sieves are fragile and the integrity of the mesh should be checked frequently (see appendix B). 7.2.1.5 Determine the mass of material passing the test sieve as M1 M2. 7.2.2 Sieving the dried residue 7.2.2.1 Nest the clean and
41、 dry sieves on a fitting receiver in order of increasing aperture size from bottom to top. Place the dried residue on the top coarsest sieve and cover with a fitting lid. Either by hand or using the mechanical sieve shaker (5.5), shake the sieves for a sufficient time to separate the test sample int
42、o the size fractions determined by the sieve apertures used. NOTEExperience has shown that the preliminary separation (7.2.1) does not necessarily remove all the particles smaller than 75 m because of capillary action of water on particle surfaces. It is therefore necessary to incorporate a 75 m tes
43、t sieve in the series of test sieves used to sieve the dried residue. Nominal size of material Minimum mass of test portion mm kg 6350 5035 4015 285 202 141 100.5 60.2 50.2 30.2 30.1 1) At the time of publication, BS 812-104 is in preparation. When published, it will supersede 7.2 of BS 812-1:1975.
44、BS 812-103.1:1985 BSI 12-19983 7.2.2.2 When the mechanical sieve shaker is used, after sieving, check that separation is complete by briefly hand sieving. When sieving is done by hand alone start with the coarsest sieve and shake each sieve separately over a clean tray or receiver until not more tha
45、n a trace passes, but in any case for a period of not less than 2 min. Do the shaking with a varied motion, backwards and forwards, left to right, circular, clockwise and anti-clockwise, and with frequent jarring so that the material is kept moving over the sieve surface in frequently changing direc
46、tions. Do not force materials through the sieve by hand pressure but placing of particles is permitted. Break lumps of agglomerated material which consist of particles representative of the bulk by gentle pressure with the fingers against the side of the sieve. 7.2.2.3 Record any extraneous material
47、 not representative of the bulk that will not readily break down into individual particles, such as clay lumps, and remove from the sieve for separate weighing. 7.2.2.4 Do not apply pressure to the surface of the sieve to force particles through the mesh. Light brushing with a soft brush on the unde
48、rside of the sieve may be used to clear sieve openings. Light brushing with a fine camel-hair brush may be used on the 150 m and 75 m sieves to prevent agglomeration of the powder and blinding of the apertures. Do not use stiff or worn-down brushes for this purpose. 7.2.2.5 In order to prevent blind
49、ing of the sieve apertures by overloading, ensure that the mass of aggregate retained on the sieve at completion of the operation does not exceed the value for that sieve shown in Table 3. NOTE 1Some sample masses shown in Table 1 will thus require additional operations on some sieves, as described in 7.1. NOTE 2In some cases it may be possible to reduce sufficiently the load on a sieve by incorporating an intermediate sieve into the test series. 7.2.2.6 Weigh the material retained on each sieve, together with any material cleaned from the
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