BS 5835-1-1980 Recommendations for testing of aggregates - Compactibility test for graded aggregates《集料试验推荐标准 第1部分 集料压实性分级实验》.pdf

1、BRITISH STANDARD BS 5835-1: 1980 Incorporating Amendment Nos. 1, 2 and 3 Recommendations for Testing of aggregates Part 1: Compactibility test for graded aggregates UDC 691.322:620.1:539.58BS5835-1:1980 This British Standard, having been prepared under the directionof the Cement, Gypsum,Aggregates a

2、nd QuarryProducts Standards Committee, was published underthe authority of the Executive Board and comes intoeffect on 30 June1980. BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference CAB/2 Draft for comment 78/13448 DC ISBN 0 580 11256 X Cooperating org

3、anizations The Cement, Gypsum, Aggregates Quarry Products Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Association of Consulting Engineers* Federation

4、of Civil Engineering Contractors* Association of County Councils Federation of Stone Industries Association of Metropolitan Authorities Gypsum Products Development Association Autoclaved Aerated Concrete Products Institute of Quarrying Association Institution of Civil Engineers* British Precast Conc

5、rete Federation Ltd.* Institution of Highway Engineers* British Quarrying and Slag Federation* Institution of Municipal Engineers* British Railways Board Institution of Public Health Engineers* British Ready Mixed Concrete Association Institution of Structural Engineers* British Steel Industry Insti

6、tution of Water Engineers and Cement Admixtures Association Scientists* Cement and Concrete Association* National Federation of Building Trades Cement Makers Federation* Employers Chemical Industries Association National Federation of Terrazzo-mosaic Concrete Society Limited* Specialists Department

7、of the Environment (Building Natural Environment Research Council Research Establishment)* (Institute of Geological Science) Department of the Environment (Housing and Royal Institute of British Architects* Construction) Royal Institution of Chartered Surveyors Department of the Environment (PSA)* S

8、and and Ballast Hauliers and Allied Trades Department of the Environment (Transport Alliance and Road Research Laboratory)* Sand and Gravel Association Limited* Department of Transport* Society of Chemical Industry The organizations marked with an asterisk in the above list, together with the follow

9、ing, were directly represented on the committee entrusted with the preparation of this British Standard: Asphalt and Coated Macadam Association Concrete Block Association Association of Lightweight Aggregate County Surveyors Society Manufacturers Electricity Supply Industry in England and Brick Deve

10、lopment Association Wales British Ceramic Research Association Greater London Council British Civil Engineering Test Equipment Institute of Building Manufacturers Association Institute of Concrete Technology Calcium Silicate Brick Association Limited Mortar Producers Association Ltd. Amendments issu

11、ed since publication Amd. No. Date of issue Comments 4198 March 1983 4435 December 1983 5578 April 1987 Indicated by a sideline in the marginBS5835-1:1980 BSI 03-1999 i Contents Page Cooperating organizations inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 General 1 5 Sampl

12、ing 1 6 Preparation of test material 1 7 Apparatus 2 8 Test procedure 2 9 Calculations and reports of results 3 Figure 1 Compaction mould apparatus 6 Figure 2 Compaction rig assembly 7 Figure 3 A suitable test sheet, with worked examples 8 Figure 4 Idealized plot of test results on a mass basis 9 Fi

13、gure 5 Typical test results, plotted on a mass basis 10 Figure 6 Typical test results, plotted on a volumetric basis 11 Figure 7 A flow diagram showing the test procedure 12 Publications referred to Inside back coverBS5835-1:1980 ii BSI 03-1999 Foreword These recommendations supplement BS 812 “Metho

14、ds for sampling and testing of mineral aggregates, sands and fillers”, which at present includes neither a test that determines the bulk density of graded aggregates at high levels of compaction, nor a test for “optimum moisture content”. Tests for these properties are included in BS1377 “Methods of

15、 test for soil for civil engineering purposes”, but these have been found to be unreliable when applied to the aggregates that are commonly used for road sub-bases and base materials. The recommendations are based on work carried out at the Transport and Road Research Laboratory of the Department of

16、 the Environment and the Department of Transport, and the committee responsible felt that the publication of this document would encourage the wider use of a standardized approach to compactibility testing. Subject to minor changes that will be made if such wider use reveals a need to amend apparatu

17、s or procedure, it is intended that this standard will be superseded by an addition to BS812 in due course. 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 S

18、tandard 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, pages1 to 14, an inside back cover and back cover. This standard has been updated (see copyright date) and may have had amendments incorpo

19、rated. This will be indicated in the amendment table on theinside front cover.BS5835-1:1980 BSI 03-1999 1 1 Scope This Part of BS5835 makes recommendations for testing the compactibility of graded aggregates, particularly those used in roadbases and sub-bases. 2 References The titles of the standard

20、s 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 BS892 and BS2787 apply, with the following additions. 3.1 moisture content the mass of water that can be removed from the ag

21、gregate by heating at 105C, expressed as a percentage of the mass of the dry aggregate 3.2 initial moisture content the moisture content of the aggregate before compaction 3.3 residual moisture content, W R the moisture content of the aggregate after compaction 3.4 optimum moisture content the moist

22、ure content at which the specified amount of compaction produces the peak value of (dry) bulk density (seeFigure 4.) NOTEThe term “optimum moisture content” can be abbreviated to “OMC”. 3.5 pessimum moisture content the moisture content at which the specified amount of compaction produces the lowest

23、 value of (dry) bulk density (see Figure 4) 3.6 saturation the condition when all air in the voids within and between the particles in an aggregate at a given level of bulk density is displaced by water 3.7 (dry) bulk density, B the ratio of the mass of a sample of (dry) aggregate to the volume of a

24、 standard container required to contain that sample NOTEPeak (dry) bulk density is the highest mean value found in any complete set of compactibility tests. 3.8 proportion of volume occupied by solids, V s the volumetric equivalent of (dry) bulk density NOTEPeak proportion of volume occupied by soli

25、ds is the highest mean value found in any complete set of compactibility tests. 3.9 particle density, P the average mass per unit volume of a sample of individual particles of oven-dried aggregate as determined using the test methods described in clause 5 of BS812-2:1975 NOTEThis term is roughly syn

26、onymous with the term “specific gravity” used in BS1377. The term “relative density” is now preferred. 3.10 water absorption value, W A the mass of water held in the voids within particles of aggregate. This, together with the free water around the particles, gives the total moisture content express

27、ed as a percentage of the dry mass of the aggregate, as determined using the test methods described in clause 5 of BS812-2:1975 4 General Vibrating hammer compaction tests on graded aggregates give an indication of their packing properties. When such tests are carried out at moisture contents coveri

28、ng a sufficient range, they can give estimates of those levels of bulk density that are likely to be achieved in field conditions, and also of the effects of moisture content upon bulk density levels. It is usually, but not always, possible to identify optimum moisture contents. The test described i

29、s suitable for aggregates having a nominal maximum size not exceeding37.5mm. Materials used as sub-bases may include particles as large as50mm. These should be removed during the sampling stage (see clause5 ). 5 Sampling The bulk sample for this test should be taken in accordance with clause 5 of BS

30、812-1:1975, and the method used should be reported. Particles larger than37.5mm should be removed and discarded. The proportion by mass of discarded material should be recorded, and given in the report. 6 Preparation of test material Representative portions of aggregate for testing should be prepare

31、d from the bulk sample so that the mass of oven-dry aggregate in each portion lies in the range of2.4kg to2.6kg. Care should be taken to minimize variations in grading between these replicate portions.BS5835-1:1980 2 BSI 03-1999 If a decision has been made to test only the dry material, then only fi

32、ve oven-dry portions will usually be required. These should be stored in sealed containers until required for testing. For each level of initial moisture content above zero, a set of five portions should be taken. Water should be added to, and mixed with, each of the five portions in each set, to ra

33、ise their individual moisture contents to within 0.1% of the required initial moisture content. Each of the wetted portions should be stored in a sealed, water-tight container for at least12h before testing, to ensure thorough wetting. If compaction tests are to be carried out to define the relation

34、 between moisture content and (dry) bulk density over the whole range of moisture contents from zero to beyond optimum moisture content (seeFigure 4), at least25portions should be prepared. NOTEIf the primary purpose is to measure optimum moisture content, it is usually best to select three levels o

35、f initial moisture content (e.g.4%,6% and 8%) to span the likely value of optimum moisture content. Tests on the15portions required by this procedure may be sufficient, but it may be necessary to carry out further tests at other moisture contents. A guide to the usefulness of tests at any particular

36、 moisture content may be gained by plotting the results as they are obtained (seeclause9 andFigure 3, Figure 4 andFigure 5). Moreover, if residual moisture contents are significantly lower than initial moisture contents, there is an implication that saturation moisture content has been reached, and

37、thus it would be pointless to make up portions at even higher initial moisture contents. 7 Apparatus NOTEThe design of the apparatus required in7.1, 7.2, 7.3, and7.4 is subject to crown copyright. The Secretary of State for Transport has agreed withBSI to make available, through his Transport and Ro

38、ad Research Laboratory, licences to market and manufacture this apparatus on non-discriminatory terms in the form of royalty payments of 5% of the net selling price of the apparatus. Applicants for licences should apply to the Director, Transport and Road Reasearch Laboratory, Department of Transpor

39、t, Old Wokingham Road, Crowthorne, RG116AU. The following apparatus is required. 7.1 A standard compaction mould, comprising a body, a base, filter assembly and an anvil. Details of the standard mould are shown inFigure 1. The cross-sectional area of the mould, given to the nearest10square millimetr

40、es, should be stamped on the side of the body. NOTEThe anvil is fitted with a pair of rubber O-rings, which will suffer wear. In time this will allow fines to be forced past the O-rings during compaction. Replacement O-rings should therefore be kept and fitted when necessary. 7.2 An electric vibrati

41、ng hammer, having a power consumption of900W and operating at a frequency of about33Hz, and equipped with a special shank (seeFigure 1 andFigure 2). NOTEIt is important that the vibrating hammer should be properly maintained in accordance with the manufacturers instructions and that its working part

42、s are not worn. To ensure good working order, overhauls should be carried out not less frequently than every50h of operation, or every six months, whichever is the shorter. 7.3 A loading frame to support the hammer and mould and to provide a steady downward force of450 10N. The design for the frame

43、is shown in Figure 2. NOTEBecause vibrating hammers of the type used in this test can emit noise levels of up to100dB(A), the compaction rig may be housed in a noise-reducing cabinet. A suitable design for a cabinet is also shown inFigure 2. Other, cheaper noise-reduction devices may be satisfactory

44、, but at least some precautions should be taken. 7.4 A depth gauge, clearly readable, to measure the distance between the top of the mould and the upper surface of the anvil to an accuracy of0.1mm or better. NOTEIt may be necessary to modify a standard depth gauge to fit into the hole in the anvil.

45、7.5 A balance, with a capacity of at least4kg, readable and accurate to1g. 7.6 A stop-watch or stop-clock or an automatic timer to control the vibrating hammer. 7.7 A supply of filter papers,150mm in diameter. “Whatman grade 113” has been found to be suitable. 7.8 A supply of non-corrodible, waterti

46、ght storage containers, having a capacity of about two litres and with lids that can be sealed. 7.9 Apparatus for the determination of particle density and water absorption, in accordance with clause5 of BS 812-2:1975. 7.10 Apparatus for the determination of moisture content, in accordance with clau

47、se7 of BS 812-2:1975. 7.11 Apparatus for the determination of particle size distribution, in accordance with clause7 of BS 812-1:1975. Washing and decantation will usually be appropriate (see7.1.6 of BS812-1:1975). (Alternatively apparatus for test7a of BS1377:1975 may be employed.) 8 Test procedure

48、 NOTEA flow diagram showing the essential steps in the test is given inFigure 6. 8.1 Compaction test. Before each compaction test, check the compaction mould to ensure that it is thoroughly clean and dry. Assemble the mould body, base, filter plates and fibre filter taking care to ensure that the pa

49、rts fit together properly. Tighten the hand screws to full tightness.BS5835-1:1980 BSI 03-1999 3 Lay two filter papers flat on the bottom of the mould and insert the anvil into the mould so that it touches the upper filter paper. Apply the vibrating hammer to the anvil for about5s to ensure that it is properly bedded. Measure carefully the depth between the bottom of the small hole within the half-ball in the anvil and the top of the mould. This should be recorded to an accuracy of0.1mm. The apparatus should then be dismantled. Repeat this process to obtain fi