BS 812-1_1975

B8U BSI BS*KB12 P A R T * L 7 5 W L b 2 4 b b î 00224Lb O =

BS 812 : Part I : 1975 UDC [625.7.07 : 620.11 : 620.1 1

Testing aggregates 0

Part I . Methods for determination of particle size and shape

Amendments issued since publication

Amd. No. Date of issue Text affected

2069 August 1976 Indicated by a line in the margin

4572 July 1984 Indicated by a line in the margin

4875 August 1985 Indicated by a line in the margin

British Standards Institution 2 Park Street * London W I A 2BS Telephone O1 -629 9000 Telex 266933

COPYRIGHT British Standards Institute on ERC Specs and StandardsLicensed by Information Handling ServicesCOPYRIGHT British Standards Institute on ERC Specs and StandardsLicensed by Information Handling Services

This British Standard, hab iiig been approved by the Road Engineering Industry Standards Comniiitee, was published tinder the authority of the Executive Board on 29 August 1975. j? British Standards Institution, 1975 BS 812 first published October 1938 and rebised in 1943, 1951, 1960 and 1967. BS 812:Part 1 first published August 1975

ISBN: O 580 08744 1

Copyr igh t Users of British Standards are reminded that copyright subsists in all BSl publications. No part of this publication may be reproduced in any form without the prior permission in writing of BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols and size, type, or grade designations. Enquiries by post should be addressed to the Publications Manager, British Standards Institution, Linford Wood, Milton Keynes MK I4 6LE. The number for telephone enquiries is 01-837 8801 and for telex 23218.

C o n t r a c t r equ i r emen t s Attention i s drawn to the fact that this British Standard does not purport to include all the necessary provisions of a contract.

Revision of British S t a n d a r d s In order to keep abreast of progress in the industries concerned, British Standards are subject to periodical review. Suggestions for improvements will be recorded and in due course brought to the notice of the committees charged with the revision of the standards to which they refer.

British Standards are revised. when necessary. by the issue either of amendment slips or of revised editions. I t is important that users of British Standards should ascerîain that they are in possession of the latest amendments or editions. Full information on all BSI publications, numbering over 9000 will be found in the ES1 Catalogue. This information is supplemented by details published each month in ES1 Nens of new publications. revisionsand amendments.

ES/ Hens is available to Subscribing Members of the Institution. All other publications may be purchased direct from Sales Department. Enquiries concerning subscribing membership, which has considerable advantages, will be welcomed. and should be made to Subscriptions Department. Both departments are located at:

Linford Wood, Miiton Keynes MK14 6LE (Telephone 0908 320033: Telex 825777).

The following BSI references relate to the work on this standard: Committee reference RDE/5 Draft for comment 72/43777 D C

Co-operating organizations

The Road Engineering Industry Standards committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations:

*Asphalt and Coated Macadam Association Association of Consulting Engineers

*British Quarrying and Slag Federation *British Tar Industry Association *Cement and Concrete Association *Concrete Society (Design and Development Divisional

Committee) Contractors' Plant Association

*County Surveyors' Society *Department of the Environment *Department of the Environment, Transport and Road

Research Laboratory Federation of Civil Engineering Contractors Federation of Manufacturers of Construction Equipment and Cranes

*Greater London Council Institute of Petroleum Institute of Quarrying

*Institution of Civil Engineers *Institution of Highway Engineers *Institution of Municipal Engineers Institution of Structural Engineers Ministry of Defence Refined Bitumen Association Limited Road Emulsion Association Limited Road Surface Dressing Association

*Sand and Gravel Association Limited Society of Chemical Industry

The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of the British Standard:

Association of London Borough Engineers and Surveyors Department of the Environment (Building Research

Natural Environment Research Council-lnstitute of Establishment)

Geological Science

8601 -5-2k-6


- - _p_ - B S I BS*ôL2 PART*3 75 M Lb24bbî 0022437 2 =

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BS 812 : Part I : 1975

Page Inside front cover Co-operating organizations

Foreword 2

Contents

Methods 1. Scope 2. References 3. Reporting 3.1 General 3.2 Certificate of sampling 4. Text deleted 5. Text deleted 6. Text deleted 7. 7.1’ Text deleted 7.2 Determination of clay, silt and dust in

7.3 xeaek&cl 7.4 Text deleted 7.5 Determination of angularity number 7.6 Text deleted

Determination of particle size and shape

fine or coarse aggregates

Foreword y-

‘This Part of BS 8 12 has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Standards Policy Committee. BS 812 was first published in 1938 and subsequently revised in 1943,1951,1960 and 1967 and this 1975 edition of BS 812 was originally published in four separate Parts. Subsequent publication of BS 812 : Parts 102, 103, 105 (Sections 105.1 and 105.2) and 106 has superseded many of the tests originally specified in this Part. Reference should be made to BS 812 : Part 101 for general guidance on testing aggregates, precision of test methods and variance arising from sampling errors. Some of the tests in other Parts of this standard are of limited application, and advice on the use of simple tests is given, for example, when they can be used for a preliminary sorting of aggregates to see whether more expensive testing is justified. Compliance with a British Standard does not of itself confer immunity from legal obligations.’

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Page Appendix A. Text deleted

Tables 1. Table deleted 2. Table deleted 3. Table deleted 4. Table deleted 5 . Table deleted 6. Table deleted 7. Mass of sample for sedimentation method 8. Mass of sample for decantation method 9. Table deleted

10. Table deleted

Figures 1. Figure deleted 2 . Figure deleted 3. Figure deleted 4. Sedimentation apparatus for deterinination

5. Figure deleted 6. Text deleted’

of clay, fine silt and fine dust content

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E S 1 BS*A12 P A R T * 1 7 5 W 1 6 2 4 b 6 7 0 0 2 2 4 1 8 4

BS 812 : Part I : 1975

I Testing aggregates I Part 1. Methods for determination of particle size and shape

I “1. Scope ---- I ‘This Part of BS 812 describes three methods for the

determination of clay, silt and dust in fine or coarse aggregates and a method for the determination of the

._ - angularity number.’ ._

Clairse 6. Text deleted

Table 2. Table rleleted

2. References

The titles of the British Standards referred to in this standard are listed on the inside back cover.

3. Reporting

3.1 General, The report shall affirm that the tests were done in accordance with this standard.

shall be described with reasons for the departure and, if possible, estimates of its effect on the test results. The report shall also include details of any special processing of the sample, other than that required by the test methods, carried out in the laboratory. For example, crushing to provide larger quantities of smaller sizes or the separation of constituents from an as-dug gravel. 3.2 Certificate of sampling. The report shall affirm that a certificate of sampling was received with the sample and shall declare all the information given on the certificate. If a certificate was not received this shall be stated in the report.

Any departure from the specified test procedure

Table 3. Table delefed

7.1 Text deleted. Superseded by BS 812 : Part 103.

Table 4. Table deleted.



7.2 Determination of clay, siit and dust in fine or coarse aggregates 7.2.1 Introduction. Three methods are described. The first by sedimentation detects material finer than 20 pm, the second by decantation detects materials finer than 75 prn. The third method is a field settling method forming a guide only to the presence of clay and silt in sand. 7.2.2 Sampling. The sample for these tests shall be taken in accordance with BS 8 12 : Part 102.

7.2.3 Sedimentation method 7.2.3.1 General. This is a gravimetric method for determining the clay, fine silt and fine dust. which includes particles up to 20 pm. Differences in the nature and density of materials or in the temperature at the time of testing may vary the separation point. 7.2.3.2 Apparatus and solution. The following is required. 7.2.3.2.1 A watertiglzt screw-toppedglass jar of dimensions similar to a 1 kg fruit preserving jar (for fine aggregate only). 7.2.3.2.2 A device for rotating the jar about its long axis, with this axis horizontal, at a speed of 80 f 20 rev/min ( f x fine aggregate only).

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BS 812 : Part I : 1975

7.2.3.2.3 A $sed depth scditiinitat ion pipette generally as described in BS 3406:Part 2, of approximately 25 ml capacity and of the general form indicated in figure 4. This consists mainly of a pipette (A) fitted at the top with a two-way tap (B) and held rigidly in a clamp which can be raised or lowered as required, and which is fitted with a scale (D) from which the changes in height of the pipette can be read.

The volume of the pipette (A), including the connecting bore of the tap (B), is determined by fillingwith distilled water, reversing the tap so that the water is run out into a bottle, weighing and calculating the volume.

L

E,

C -

e’

A /

,Scale graduated

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i 1000 m! ; measuriny cylinder I I I I I l

I I

Figure 4. Sedimentation apparatus for determination of clay, fine silt and fine dust content

7.2.3.2.4 A 1000 ml measuring cylinder complying with the requirements of BS 604. 7.2.3.2.5 A scale or balancc of capacity not less than 10 kg, accurate to I g. 7.2.3.2.6 A scale or halaiice of capacity not less than 160 g, accurate to 0.001 g,

7.2.3.2.7 A well iientilatedoven, thermostatically controlled to maintain a temperature of 105 f 5 “C. 7.2.3.2.8 Distilled (or deionized) iiuter. Through- out this method when reference is made to distilled water deionized water may be used instead. 7.2.3.2.9 A solution containing 8 g of sodium oxalate per litre ojdistilled irater. For use, this stock solution is diluted with distilled water to one tenth (¡.e. 100 ml diluted with distilled water to 1 litre). 7.2.3.3 Tc~st sainple. The sample for test shall comply with the appropriate minimum mass given in table 7 and be taken from the original sample received at the laboratory either by quartering or by means of a sample divider, as described in BS 812 : Part 102. It shall be brought to an air-dry condition by drying a t room temperature or by heating at a temperature not exceeding 1 10 “C.

Table7. Mass of sample for sedimentation method

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Nominal size

mm 63 to 28 20 to 14 10 to 6 5 or smaller

Minimum mass of sample

kg 6 I O. 5 0.3

Ail-in aggregates shall be separated into fine and coarse fractions by sieving on a 5.00 mm BS test sieve and the two samples so obtained shall be . tested separately. 7.2.3.4 Test procedure, The test procedure shall be as follows.

(a) Methodforjne aggregate. Weigh approximately 0.3 kg of the sample in the dry condition passing the 5.00 mm BS test sieve and place i t in the screw-topped glass jar, together with 300 ml of the diluted sodium oxalate solution. Fix the rubber washer and cap, taking care to ensure watertightness. Then rotate the jar about its long axis, with this axis horizontal, at a speed of 80 f 20 revlmin for a period of 15 min.

the 1000 ml measuring cylinder and wash the residue by gentle swirling and decantation of successive 150 ml portions of diluted sodium oxalate solution, the washings being added to the measuring cylinder until the volume is made up to 1000 ml. Complete the determination as described in 7.2.3.4(c). (b) Metltod. for coarse aggregate. Place the weighed sample in a suitable container, cover it with a measured volume of diluted sodium oxalate solution, agitate it vigorously to remove all adherent fine material and transfer the liquid suspension to the 1000 mi measuring cylinder. Repeat this process as necessary until all clayey material has been transferred to the measuring

At the end of 15 min pour the suspension into

a

a

a

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m BSI BS*âL2 P A R T * L 75 1 6 2 4 6 6 9 O022420 2 I

BS 812 : Part 1 : 1975

cylinder. Make up the volume to 1000 ml with the diluted sodium oxalate solution and complete the determination as described in 7.2.3.4(c). (c) Finalprocedure. Thoroughly mix the suspension in the measuring cylinder by inversion and immediately place the cylinder and contents in position under the pipette. Then gently lower the pipette (A) until the tip touches the surface of the liquid, and then lower it a further 100 mm into the liquid. 4 min after placing the measuring cylinder in position fill the pipette (A) and the bore of tap (B) by opening (B) and applying gentle suction a t (C). Asmall surplus may be drawn up into the bulb between tap (B) and tube (C), but this shalI be allowed to run away and any solid matter shall be washed out with distilled water from (E). Then remove the pipette from the measuring cylinder and run its contents into a weighed container, any adherent solids being washed into the container by distilled water from (E) through the tap (B).

to constant mass, cool and weigh it. Dry the contents of the container at 105 f 5 "C

e 7.2.3.5 Calculations. The proportion of clay, fine silt and fine dust shall then be calculated from the following equation :

Percentage of clay, fine silt and fine dust

= - ( M1 V - 0.8)

M1 is the mass of the original sample (g); M2 is the mass of the dried residue (g); V is the volume of the pipette (mi); 0.8 is the mass of sodium oxalate (g) in 1 litre of

the diluted solution. NOTE. No correction is made for water-soluble salts which may be present in the sand, since the amount of such salts is normally small. 7.2.3.6 Reporting of results. The clay, fine silt and fine dust content shall be reported as a percentage to the nearest whole number above 10 %, to the nearest 0.5 % between and including 10 % and 0.5 %, and to the nearest O. 1 % below 0.5 %. 7.2.4 Decantation method 7.2.4.1 General. This is a method for determining the amount of material passing a 75 pm BS test sieve. 7.2.4.2 Apparatus. The following apparatus is required. 7.2.4.2.1 A scale or balance of suitable capacity accurate to 0.05 % of the mass of the test sample. 7.2.4.2.2 A well ventilated oven thermostatically controlled to maintain a temperature of 105 f 5 "C. 7.2.4.2.3 A 75 pm BS 410 full tolerance test sieve and a nesting sieve to protect the 75 pm test sieve, e.g. a 1.18 mm sieve. 7.2.4.2.4 A container of a size sufficient to contain the sample covered with water and to permit vigorous agitation without loss of any part of the sample or water.

100 1000 M2

where

0

O 5

7.2.4.3 Test sample. The sample for test shall comply with the appropriate minimum mass given in table 8, and be taken from the original sample received at the laboratory either by quartering or by means ofa sample divider, as described in BS 8 12 : Part 102. Table 8. Mass of sample for decantation method

Nominal size

mm 63 to 28 20 to 14 10 to 6 5 or smaller

Minimum mass of sample

kg 6 1 O. 5 0.3

7.2.4.4 Test procedure. Dry the test sample in shallow trays in the oven for 24 f 0.5 h, at a temperature of 105 f 5 "C, cool and weigh it (mass A).

Then place the test sample in the container and add enough water to cover it. Agitate the contents of the container vigorously and immediately pour the wash water over the sieves, which have previously been wetted on both sides and arranged with the coarser sieve on top.

The agitation shall be sufficiently vigorous to result in the complete separation from the coarse particles of all particles finer than the 75 pm BS test sieve, and to bring the fine material into suspension in order that it will be removed by decantation of the wash water. Take care to avoid, as far as possible, decantation of the coarse particles of the sample. Repeat the operation until the wash water is clear. Return all material retained on the sieves to the washed sample. Dry the washed aggregate as before, cool and weigh it (mass B). 7.2.4.5 Calculfitions. The results shall be calculated from the following equation :

Percentage of material passing a 75 pm BS

test sieve = - x 100

A is the mass of oven-dried sample (g) ; B is the mass of portion retained on the 75 pm

7.2.4.6 Reporting of results. The amount of material finer than a 75 pm BS test sieve shall be reported as a percentage to the nearest whole number above 10 %, to the nearest 0.5 % between and including 10 % and 0.5 %, and to the nearest O. 1 % below 0.5 %. 7.2.5 Fieldsettling test. This is an approximate volumetric method, which has its main application in the routine checking of supplies of sand from a given source, when the results can be correlated with those obtained by the decantation method; it is not applicable to crushed stone sands or coarse aggregates.

A - B A

where

BS test sieve (g).


III_- _ - ~ BSI BS*812 P A R T * 1 75 lb24bb9 0 0 2 2 4 2 3 4 m

BS 812 : Part 1 : 1975 _-

The test is intended as no more than a guide to ' L the percentage of silt and clay, since the result will vary according to the fineness and type of clay.

Prepare a 1 % solution of sodium chloride (common salt) in water. Two teaspoonsful of salt to 1 litre of water will suffice. Pour 50 ml of this solution into a 250 ml measuring cylinder, Gradually add sand in the condition as received until the volume of the sand is about 100 ml. Then make up the volume to 150 ml by the addition of more salt solution.

Shake the mixture vigorously until adherent clayey particles have been dispersed, and then place the cylinder on a level bench and gently tap until the surface of the sand is level.

After three hours standing the height of the silt visible above the sand-silt interface shall be expressed as a percentage of the height of the sand below the interface to the nearest whole number.

7.3 Text deleted, Superseded by BS 817 : Section 105.1.


Figure 5. Figure deleted. I

- 7.4 Determination of elongation index 7.4 Text deleted. Superseded by BS 812 :

_-- 1 .Section105.2 .~ -

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BS 812 : Part 1 : 1975

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7.5 Determination of angularity number 7.5.1 General. The angularitynumber is determined from the proportion of voids in a sample of aggregate after compaction in the specified manner. This property is used mainly in the design of mix proportions and in research.

Angularity or absence of rounding of the particles of an aggregate is a property which is of importance because it affects the ease of handling of a mixture of aggregate and binder (e.g. the workability of concrete) or the stability of mixtures that rely on the interlocking of the particles. The least angular (most rounded) aggregates are found to have about 33 % voids and the angularity number is defined as the amount by which the percentage of voids exceeds 33. The angularity number ranges from O to about 12.

Since considerably more compactive effort is used

than in the test for bulk density and voids (see 6.1 of Part 2) the percentage of voids will be different. Weaker aggregates may be crushed during compaction and the results will be anomalous if this method is applied to any aggregate which breaks down during the test.

7.5.2 Sampling. The sample for this test shall be taken in accordance with BS 8 12 : Part 102. I 7.5.3 Apparatus. The following apparatus is required. 7.5.3.1 A metal cylinder closed at one end, of about 0.003 m3 volume, the diameter and height of which should be approximately equal (e.g. 150 mm and 150 mm).

The cylinder shall be made from metal of a thickness not less than 3 mm and shall be of sufficient rigidity to retain its shape under rough usage. 7.5.3.2 A straight metal tamping rod of circular cross section 16 mm in diameter and 600 mm long rounded at one end. 7.5.3.3 A balance or scale of capacity 10 kg, accurate to I g. 7.5.3.4 A metal scoop approximately 200 mm x 120 mm x 50 mm (Le. about 1 litre heaped capacity). 7.5.3.5 BSperforated-plate test sieves from 20.0 mm to 5.00 mm aperture size (but see note to 7.5.5(a)). 7.5.4 Calibration of the cylinder. The cylinder shall be calibrated by determining to the nearest gram the mass of water at 20 f 2 “C required to fill it SQ

that no meniscus is present above the rim of the container (mass C).

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BS 812 : Part I : 1975

7.5.5 Prcpmitioii qf‘rhe test sariiple. The test sample shall be prepared as follows,

(a) The amount of aggregate available shall be sufficient to provide, after separation on the appropriate pair of sieves, at least 10 kg of the predominant size as determined by sieve analysis on the BS test sieves.

retained between the appropriate pair of BS test sieves from the following list:

20.0 mm and 14.0 mm; 14.0 mm and 10.0 mm; 10.0 mm and 6.30 mm; 6.30 mm and 5.00 mm.

The test sample shall consist of aggregate

NOTE. In testing aggregates larger than 20.0 mm the volume of the cylinder should be greater than 0.003 m3, but for aggregates smaller than 5.00 mm a smaller cylinder may be used. The procedure should be the same as with the 0.003 m3 cylinder, except that the amount of compactive effort (mass of tamping rod x height of fall x number of blows) should be proportioned to the volume of rhccylinder used. (b) The aggregate to be tested shall be dried for at least 24 h in shallow trays in a well ventilated oven at a temperature of 105 f 5 OC, cooled in an airtight container and tested.

7.5.6 Testprocedure. Fill the scoop and heap it to overflowing with the aggregate, which shall be placed in the cylinder by allowing it to slide gently off the scoop from the least height possible.

Subject the aggregate in the cylinder to 100 blows of the tamping rod at a rate of about two blows per second. .4pply each blow by holding the rod vertical with its rounded end 50 mm above the surface of the aggregate and releasing it so that it falls freely. Do not apply any force to the rod. Evenly distribute the 100 blows over the surface of the aggregate.

Repeat the process of filling and tamping exactly as described above with a second and third layer of aggregate; the third layer shall contain just sufficient aggregate to fill the cylinder level with the top edge before tamping.

tamped, fill the cylinder to overflowing, and strike off the aggregate level with the top, using the tamping rod as a straight-edge.

Then add individual pieces of aggregate and ‘roll them in’ to the surface by rolling the tampingrod

After the third layer of aggregate has been

across the upper edge of the cylinder, and continue this finishing process as long as the aggregate does not lift the rod off the edge of the cylinder on either side. Do not push in or otherwise force down the aggregate, and apply no downward pressure to the tamping rod, which shall roll in contact with the metal on both sides of the cylinder.

nearest 5 g.

calculate the mean mass of aggregate in the cylinder (mass M ) . If the result of any one determination differs from the mean by more than 25 g, three additional determinations shall immediately be made on the same material, and the mean of all six determinations calculated (mass M ) . 7.5.7 Calculations. The angularity number of the aggregate shall be calculated from the equation:

Then weigh the aggregate in the cylinder to the

Make three separate determinations, and

100 M Angularity number = 67 - -

CGA where

M is the mean mass of aggregate in the

C is the mass ofwater required to fill the

GA is the relative density on an oven-dried basis

cylinder (g);

cylinder (g);

of the aggregate determined in accordance with clause 5 of Part 2 of this standard.

7.5.8 Reporthg of results. The angularity number shall be reported to the nearest whole number.

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BSI B S * ä 1 2 P A R T * L 7 5 1 6 2 4 6 6 9 0 0 2 2 4 2 4 T

BSI publications referred to in this standard This standard makes reference to the following British Standards: BS 4 i0 Test sieves US 604 Graduated measuring cylinders

. BS 812 Testingaggregates Part 101 Guide tosamplingand testingaggregates * Pari 102 Methods for sampling Part 103 Methods for determination of particle size distribution Part 105 Methods for determination of particle shape Section 105. I Flakiness index 'Section 105.2 Elongation index of coarse aggregate Pari 106 Method for determination ofsliell conte; i n coarse aggregate

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'BS 3406 Methods for the determination of particle size distribution Part 2 Recommendations for gravitational liquid sedimentation methods for powders and suspensions'. A ~

ISBN: O 580 08744 1


,- c- P I BSI BSdB12: P A R T * L 75 ‘1624667 0228200 T ’

AMD 6587

Amendment No. 4 published and effective from 30 April 1991 to BS 812 : Part 1 : 1975

Testing aggregates Part 1. Methods for determination of particle size and shape

AMD 6587 Foreword (as amended by Amendment Nos. I , 2 and 3) Delete the foreword entirely and substitute the following: ‘This Part of BS 8 12 has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Standards Policy Committee. BS 812 was first published in 1938 and subsequently revised in 1943,1951,1960 and 1967 and this 1975 edition of BS 812 was originally published in four separate Parts. Subsequent publication of BS 812 : Parts 102, 103, 105 (Sections 105.1 and 105.2) and 106 has superseded many of the tests originally specified in . this Part. Reference should be made to BS 812 : Part 101 for general guidance on testing aggregates, precision of test methods and variance arising from sampling errors. Some of the tests in other Parts of this standard are of limited application, and advice on the use of simple tests is given, for example, when they can be used for a preliminary sorting of aggregates to see whether more expensive testing is justified. Compliance with a British Standard does not of itself confer immunity from legal obligations.’

April 1991

Contents (as amended by Amendment Nos. 2 and 3) Delete the titles of clause 7.4 and figure 6 and substitute ‘Text deleted’ for each.

Clause I . Scope (as amended by Amendment Nos. I and 2) Delete the existing text entirely and substitute the foliowing: ‘1. Scope - This Part of BS 8 12 describes three methods for the determination of clay, silt and dust in fine or coarse aggregates and a method for the determination of the angularity numbër.’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clause 7.4 Determination of elongation index (as amended by Amendment No. 2) Delete the clause entirely and substitute ‘7.4 Text deleted. Superseded by BS 812 : Section 105.2’.


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BS 812-1_1975