SANS 5834-2006 Soluble deleterious impurities in fine aggregates (limit test)《在细骨料中的可溶性有害杂质(限量测试)》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 0-626-17615-8 SANS 5834:2006Edition 2.1Any reference to SABS SM 834 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 Nove

4、mber 2002)SOUTH AFRICAN NATIONAL STANDARD Soluble deleterious impurities in fine aggregates (limit test) Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Afr

5、ica SANS 5834:2006 Edition 2.1 Table of changes Change No. Date Scope Amdt 1 2006 Amended to update referenced standards and to change the designation of SABS standards to SANS standards. Foreword This South African standard was approved by National Committee StanSA SC 5120.61A, Construction standar

6、ds Cement, lime and concrete, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. A vertical line in the margin shows where the text has been technically modified by amendment No. 1. This edition cancels and replaces the first revision (SABS

7、SM 834:1994). SANS 5834:2006 Edition 2.1 1 Soluble deleterious impurities in fine aggregates (limit test) 1 Scope and field of application This standard specifies a method for measuring the effect of soluble deleterious materials in fine aggregates by comparing the compressive strength of mortar cub

8、es made from the fine aggregate in its natural state with the compressive strength of mortar cubes made from a washed sample of the same fine aggregate. 2 Normative references The following documents contain provisions which, through reference in this text, constitute provisions of this specificatio

9、n. All documents are subject to revision and, since any reference to a document is deemed to be a reference to the latest edition of that document, parties to agreements based on this specification are encouraged to take steps to ensure the use of the most recent editions of the documents listed bel

10、ow. Information on currently valid national and international standards can be obtained from the appropriate standards organization. SABS 471, Port cement (ordinary, rapid-hardening and sulphate-resisting). Amdt 1 SANS 197, Preparation of test samples of aggregates. SANS 5863, Concrete tests Compres

11、sive strength of hardened concrete SABS SM 866, Compressive and flexural strength of cement (mortar prism method). Amdt 1 SANS 50196-1/EN 196-1, Methods of testing cement Part 1: Determination of strength. Amdt 1 SANS 50197-1/EN 197-1, Cement Part 1: Composition, specifications and conformity criter

12、ia for common cements. Amdt 1 3 Material Portland cement, that complies with the requirements of SANS 50197-1 for ordinary Portland cement. Amdt 1 4 Apparatus 4.1 Two suitable gauging trowels, of length approximately 200 mm. 4.2 Moulds, equipped with base plates and suitable cover plates, and constr

13、ucted of a metal that is resistant to attack by cement mortar. The moulds are so rigidly constructed as to facilitate the SANS 5834:2006 Edition 2.1 2 removal of a moulded test specimen without damage, and so machined that, when cubical moulds are assembled and ready for use, their dimensions and in

14、terior faces are as follows: a) nominal height of mould and nominal distances between opposite faces : 50 mm to 100 mm; b) height of mould and distances between opposite faces equal to within : 0,15 mm; c) angle between adjacent interior faces and planes of top and bottom surfaces : 90 0,5; and d) i

15、nterior faces and base plate plane to within : 0,03 mm per 100 mm. Alternatively, prism moulds with dimensions as given in SANS 50196-1 may be used. Amdt 1 The base plates of moulds are of such size that the moulds are adequately supported and leakage will not occur during filling and compaction. 4.

16、3 Curing cabinet (or curing room), maintained at a temperature of 22 C to 25 C and at a relative humidity of at least 90 %. 4.4 Steam cabinet, that is of such dimensions that it will hold at least six moulds simultaneously. It is equipped with means to supply (continuously for 24 h) steam at a tempe

17、rature of 80 C to 85 C and at normal atmospheric pressure. The cabinet is so insulated and provided with a steam outlet as to ensure that the temperature of the steam in the cabinet does not vary by more than 1 C, and that the steam pressure does not exceed atmospheric pressure. 4.5 Curing bath, of

18、such dimensions that it will hold at least six test specimens simultaneously, maintained at a temperature of 22 C to 25 C. 4.6 Compression testing machine, of suitable capacity and design which complies with the requirements given in SANS 5863. If test specimens of prismatic shape (see 4.2) are used

19、, the machine platens and, if relevant, auxiliary equipment are of the design described in SANS 50196-1. 5 Preparation of test specimens 5.1 Unwashed fine aggregate 5.1.1 Mixing From the unwashed fine aggregate in the relevant test sample (see SANS 197), prepare a mortar in which the dry fine aggreg

20、ate:cement ratio is 3:1 by mass, preparing enough mortar for three test specimens, as follows: using the two trowels, mix the dry materials for 1 min on a clean, dry, non- absorbent surface, and then add enough water to produce a mortar of a consistency judged to be suitable for brick-laying purpose

21、s. The water may be added at intervals during the mixing, and mixing shall be continued for not less than 3 min and not more than 5 min after the final quantity of water has been added. NOTE A suitable mechanical mixer may be used, provided that the above mixing sequence is followed and that the mat

22、erial that adheres to parts of the mixer is scraped off at least once during the wet mixing process. SANS 5834:2006 Edition 2.1 3 5.1.2 Moulding Fill the moulds with the mortar and thoroughly compact the mortar by any suitable means. Ensure that all the moulds are filled and compacted in exactly the

23、 same manner. Cut off the excess mortar flush with the top of the mould, by drawing a straight edge across the top of the mould. Ensure that the top edge of the mould is free from loose aggregate particles, and place the cover plate in position. 5.1.3 Curing Unless the use of method 3 is necessary (

24、see 7.3), use either method 1 or method 2. Method 1. Immediately after filling, place the moulds in the curing cabinet (see 4.3) for 2 h. Transfer the test specimens (in the covered moulds) to the steam cabinet, so raise the temperature at a uniform rate that a steam temperature of 80 C to 85 C is r

25、eached in 2 h, and maintain this temperature for 24 h. Then decrease the temperature until a temperature of 22 C to 25 C is reached. Remove the test specimens from the moulds and immediately determine their compressive strength. Method 2. Immediately after filling, place the moulds in the curing cab

26、inet for 24 h 0,5 h. Remove the test specimens from their moulds and immerse them in clean water in the curing bath (see 4.5). Remove the test specimens from the curing bath 7 d 1 h after completion of moulding and immediately determine their compressive strength. Method 3. Follow the procedure for

27、method 2 above, but remove the test specimens from the curing bath 28 d 2 h after completion of moulding and immediately determine their compressive strength. 5.2 Washed fine aggregate Wash the fine aggregate as follows: add enough water to the fine aggregate to cover it completely. Stir well, and a

28、llow to stand for 24 h. Add more water until the water level is approximately 150 mm above that of the fine aggregate. Stir well and leave to stand until no fine aggregate remain in suspension. Siphon off the water to a depth of approximately 25 mm above the fine aggregate, ensuring that no solids a

29、re removed during the process. Carry out the above procedure of washing and siphoning off the water at least three times. Dry the fine aggregate at 100 C to 110 C. Make and cure three test specimens as described in 5.1, using exactly the same mixed proportions and the same cement and water:cement ra

30、tio as specified in 5.1, but using the fine washed aggregate. NOTE The colour of the supernatant water above the fine aggregate is not necessarily an indication of the presence of clay or fines since certain soluble matter can produce the same effect. If the washing is done in a glass vessel and the

31、 vessel is held against the light, the presence or absence of fine solids can be readily detected. 6 Procedure Immediately after removal of the test specimen from the curing bath or steam cabinet (as relevant), remove any loose particles, etc., by wiping the sides of the test specimen and place it (

32、on its side and without packing) in the compression testing machine. Apply the load without shock and so increase it continuously at a uniform rate that the rate of stress increase is approximately 15 MPa/min, until the test specimen fails. Repeat the test with the remaining specimens. SANS 5834:200

33、6 Edition 2.1 4 7 Expression and reporting of results 7.1 Calculate the average compressive strength, in megapascals, of each set of three test specimens by dividing the average crushing force, in newtons, of three specimens by the area of the side to which the force was applied. 7.2 Record and repo

34、rt, to the nearest 0,5 MPa, the average compressive strength of each set of three test specimens. Calculate and report the average compressive strength of the three specimens made with the unwashed fine aggregate as a percentage of the average compressive strength of the three specimens made with th

35、e washed fine aggregate. 7.3 If, when curing method 1 or method 2 is used, this reported percentage is less than the value specified in the relevant specification or less than the value agreed upon between the purchaser and supplier, disregard the result and repeat the test, using method 3. Standards South Africa