BS 812-119-1985 Testing aggregates Method for determination of acid-soluble material in fine aggregate《集料试验 细集料中酸溶物质的测定方法》.pdf

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1、BRITISH STANDARD BS 812-119: 1985 Testing aggregates Part 119: Method for determination of acid-soluble material in fine aggregate UDC 625.07 + 691.22:543.726 + 543.832BS812-119:1985 This British Standard, having been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products

2、 Standards Committee, was published under the authority of the Board of BSI and comes into effect on 31July1985 BSI 01-1999 The following BSI references relate to the work on this standard: Committee reference CAB/2 Draft for comment 82/14681DC ISBN 0 580 14544 1 Committees responsible for this Brit

3、ish 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 Concrete Block Association Association of Consulting Engineer

4、s 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 Equipment Manufacturers Association British Precast Concrete

5、 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 of the Environment (Building Research Establishment) Depa

6、rtment 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 Contractors Greater London Council Institute of Concrete Tec

7、hnology 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. National Federation of Terrazzo Mosaic Specialists Natural Envi

8、ronment 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. Date of issue CommentsBS 812-119:1985 BSI 01-1999 i Contents Page Committees responsible Insi

9、de front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Principle 1 4 Sampling 1 5 Apparatus 1 6 Reagents 1 7 Preparation of test portions 1 8 Procedure 2 9 Calculation and expression of results 2 10 Precision 3 11 Test report 3 Table 1 Examples of precision data for determination of the content of a

10、cid-soluble material 3 Publications referred to Inside back coverBS812-119:1985 ii BSI 01-1999 Foreword This Part of BS812, prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee, has been produced for the particular purpose of testing fine aggregate t

11、o be used in concrete road surfaces and concrete paving blocks. BS812-2, BS812-3 and BS812-4 are also being revised and as each of the tests, or collections of related tests, is revised, it is intended to issue it as a separate Part or Section of this standard. It is intended that other British Stan

12、dards should call up BS812 test methods as the basis of compliance. Nevertheless, it is not intended that all aggregates should be subjected regularly to all the listed tests. Specifications in other standards will refer only to the relevant test methods. Some of the tests in other Parts of this sta

13、ndard 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. It is necessary that pavement surfaces do not develop a polished surface of low skidding r

14、esistance when trafficked and it is desirable that pavement surfaces be tested for resistance to polishing. However, such a test has not yet been published as a British Standard and some authorities exclude the use of fine aggregates containing significant amounts of acid-soluble material, some of w

15、hich have been found to give poor polishing resistance. Such aggregates are excluded only because of their low resistance to polishing although they have no adverse effects on any of the other properties of the concrete. The procedure for dividing the test sample into two fractions, one passing a5.0

16、mm test sieve and retained on a 600m test sieve and the other passing a600m test sieve, and making separate determinations of acid-soluble material on each fraction fulfils the special needs of the authorities concerned with specifying fine aggregate to be used in concrete pavement surfaces. The pro

17、cedure for the determination of acid-soluble material (clause 8) may have other applications but it should be realized that the results so obtained may not correlate with processes involving, for example, other acids or acid concentrations. Reference should be made to BS812-101 for general guidance

18、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 application. Compliance with a British Standard does not

19、 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 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wil

20、l be indicated in the amendment table on the inside front cover.BS 812-119:1985 BSI 01-1999 1 1 Scope This Part of BS812 describes a method of determining the amount of acid-soluble material in both of the size fractions of fine aggregate, all passing a 5.00mm test sieve, separated by sieving on a 6

21、00m test sieve. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of BS812 the definitions given in BS812-101 and BS812-102 apply. 3 Principle The fraction of fine aggregate passing a 5.00mm test sieve is

22、separated by sieving on a 600m test sieve. A weighed test portion of each fraction is treated with hydrochloric acid and the dried residue weighed, when cool, to determine the mass of acid-soluble material extracted. NOTEThe original intention of the test was to measure acid-soluble carbonates. With

23、 some materials, however, other acid-soluble components may be present and these may contribute to a high value, particularly if digestion with acid is prolonged. 4 Sampling The sample used for the test (the laboratory sample) shall be taken in accordance with the procedure described in clause5 of B

24、S812-102:1984. 5 Apparatus 5.1 A sample divider, of size appropriate to use with fine aggregate, e.g. a riffle box as specified inBS812-102 or, alternatively, a flat scoop and a clean, flat and hard horizontal surface, e.g. a metal tray, for use in quartering. 5.2 Test sieves, with apertures of 5.00

25、mm and 600m, complying with BS410 and with fitting lids and receivers. 5.3 A balance, of 100g capacity, accurate to 0.1g or less. 5.4 Two beakers or two wide-mouth conical flasks, of500mL capacity. 5.5 Medium grade filter papers 1) . 5.6 Two filter funnels, appropriate to the diameter of the filter

26、papers. 5.7 A measuring cylinder, of 25mL capacity. 5.8 An electric hot plate, capable of being controlled to maintain the temperature of the contents of the flasks at just below boiling point. 5.9 A wash bottle. 5.10 Two evaporating basins, of about 250mL capacity. 5.11 A drying oven, capable of be

27、ing controlled to maintain a temperature of 1055C. 5.12 A desiccator, of sufficient size to hold the evaporating basin. 6 Reagents 6.1 Hydrochloric acid solution (approximately 4mol/L), prepared by diluting360mL of concentrated hydrochloric acid (p1.18) to1L with distilled water. 6.2 Distilled water

28、, complying with BS3978 or, alternatively, deionized water. 7 Preparation of test portion 7.1 Test sample Reduce the laboratory sample by the procedures described in clause 6 of BS812-102:1984 to produce a sub-sample of mass approximately 400g. If sub-division is by using a riffle box, ensure that t

29、he sample is free flowing by drying it if necessary. Sieve the sub-sample through a 5.00mm test sieve rejecting any particles retained on the sieve. The material passing the sieve is the test sample. 7.2 Test portion 7.2.1 Dry the test sample by heating at a temperature of1055C until constant mass i

30、s achieved, cool and sieve through a 600m test sieve and collect the fraction passing the sieve in a fitting receiver. To prevent blinding of the sieve apertures by overloading, place an amount of aggregate on the sieve such that the amount retained on completion of sieving is not greater than 75g o

31、n a 200mm diameter sieve or not greater than 110g on a 300mm diameter sieve. Continue sieving until not more than 1g of undersize material passes the sieve during 1min. If mechanical sieving is used, check that separation is complete by hand sieving briefly. 7.2.2 If either the material retained on

32、the sieve or that passing has a mass of less than 50g, repeat the procedure described in 7.2.1 on a new test sample produced by the procedure described in 7.1 to produce a total of at least 50g oversize and 50g undersize fractions. 1) Whatman No.40 filter papers have been found to be suitable.BS812-

33、119:1985 2 BSI 01-1999 NOTEWhen sieve analysis using the procedures described inBS812-103 2)has been carried out it is permissible to obtain the two fractions required by combining the material passing a 5.00mm test sieve and retained on all the test sieves with apertures of 600m or larger and all t

34、he material passing the 600m test sieve. 7.2.3 Use the procedures described in clause6 of BS812-102:1984 to reduce the material retained on the 600m test sieve to provide a test portion with a mass of 505g. Weigh the test portion and record its mass to the nearest 0.1g (M 1 ). 7.2.4 Similarly reduce

35、 the material passing the600m test sieve to produce a weighed test portion with a mass of 50 5g. NOTEFor some applications the procedure of separating the test sample on a 600m test sieve is not required. In those cases the dried test sample should be reduced to produce a weighed test portion with a

36、 mass of 50 5g. 8 Procedure 8.1 General Determine, separately, the acid-soluble material content of both test portions (see7.2) by the method described in 8.2. NOTEMaterial which contains clay (see8.2.4) may be difficult to filter and may give anomalous results. Improvement of filtration may be achi

37、eved by adding 1mL of polyacrylamide solution (1g polyacrylamide of relative molecular mass 5 10 6 , dissolved in 1L of distilled water) to the suspension to flocculate suspended matter. 8.2 Test procedure 8.2.1 Dry a medium grade filter paper (5.5) by heating in an oven (5.11) at a temperature of10

38、5 5 C for 60 15min. Cool at room temperature for 30min, weigh and record its mass to the nearest 0.1g (M 2 ). 8.2.2 Transfer the weighed test portion of fine aggregate fraction to a 500mL beaker or conical flask (5.4) and add 25mL of the dilute hydrochloric acid solution (6.1) and agitate the conten

39、ts of the flask. When effervescence is considerable add the acid with care to avoid loss of material. When any effervescence has ceased add a further 25mL of dilute acid and agitate. Continue adding 25mL portions of the dilute hydrochloric acid until no further effervescence occurs on adding the aci

40、d. 8.2.3 Heat the flask on the electric hot plate (5.8) until its contents are hot but not boiling, i.e. 70C to90C, and maintain at this temperature for 5min to10min. Add a further 25mL of dilute hydrochloric acid to the hot solution to confirm that reaction has ceased. If further effervescence occu

41、rs, continue adding 25mL portions of the dilute hydrochloric acid to the hot solution until no further effervescence occurs on adding acid. NOTENo further effervescence from the aggregate particles is taken as an indication of cessation of reaction. Reaction with acid should not be continued for mor

42、e than approximately 1h. 8.2.4 Remove the flask from the source of heat and decant the solution through the weighed filter paper supported in a suitable filter funnel (5.6). Add 50mL hot, but not boiling, distilled water (5.2) to the residual undissolved aggregate in the flask, agitate and decant th

43、e water through the filter paper. Repeat the washing and decanting process at least five times. NOTEVacuum filtration may give an increase in filtration rate. 8.2.5 Wash the residue from the flask into an evaporating basin (5.10) (see note) with water, ensuring that all the undissolved aggregate is

44、transferred. Decant the supernatant liquid from the basin through the filter paper. When all the liquid has been drained, place the filter paper and its contents in the evaporating basin with the residue and dry in an oven at a temperature of 1055C for16 1h or until constant mass is achieved. Cool t

45、o room temperature in a desiccator (5.12). Weigh the dried residual aggregate plus the filter paper and its contents and record the mass to the nearest0.1g(M 3 ). NOTEThe evaporating basin may be pre-weighed after drying and cooling. In this case the dried residual aggregate is weighed together with

46、 the basin and the filter paper. 9 Calculation and expressions of results Calculate the percentage loss in mass caused by acid treatment from the equation: where M 1 is the mass of dried test portion (ing); M 2 is the mass of dried filter paper (ing); M 3 is the mass of dried residue plus filter pap

47、er (ing). NOTEIf a pre-weighed evaporating basin has been used the values of M 2and M 3are slightly modified as follows: M 2 is the mass of dried filter paper plus evaporating basin (ing); M 3 is the mass of dried residue plus filter paper plus evaporating basin (ing). Express the result as the perc

48、entage acid-soluble material content of the sample to the nearest 1%. 2) In preparation. % acid-soluble material M 1 M 2 M 3 + M 1 -100 =BS 812-119:1985 BSI 01-1999 3 10 Precision The precision of the test method, including the taking of the laboratory samples according to the procedure described in

49、 clause5 of BS812-102:1984 for sampling from heaps, has been measured for two types of material. The results are given in Table 1. 11 Test report The test report shall affirm that the acid-soluble material content was determined in accordance with this Part of BS812, and whether or not a certificate of sampling is available. If available, a copy of the certificate of sampling shall be provided. The test report shall include the following additional information: a) sample identification; b) either: 1) t