SANS 5837-2008 Low density materials content of aggregates《骨料低密度材料含量》.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 978-0-626-21582-8 SANS 5837:2008Edition 2.2Any reference to SABS SM 837 is deemedto be a reference to this standard(Government Notice No. 1373 of 8

4、November 2002)SOUTH AFRICAN NATIONAL STANDARD Low density materials content of aggregates 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 Africa SANS 5837:2

5、008 Edition 2.2 Table of changes Change No. Date Scope Amdt 1 2002 Amended to update normative references. Amdt 2 2008 Amended to change the designation of SABS standards to SANS standards, with no technical changes. Foreword This South African standard was approved by National Committee StanSA SC 5

6、120.61A, Construction standards Cement, lime and concrete, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This document was published in July 2008. This document supersedes SABS SM 837:2002 (edition 2.1). SANS 5837:2008 Edition 2.2 1 Low

7、 density materials content of aggregates 1 Scope and field of application This standard specifies a method for determining the percentage, by mass, of low density materials (materials of density less than 2 000 kg/m3, e.g. coal and lignite) contained in aggregates. 2 Normative references The followi

8、ng standards contain provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreements based on this standard

9、 are encouraged to take steps to ensure the use of the most recent editions of the standards indicated below. Information on currently valid national and international standards can be obtained from the South African Bureau of Standards. SANS 3310-1/ISO 3310-1, Test sieves Technical requirements and

10、 testing Part 1: Test sieves of metal wire cloth. Amdt 1 SANS 3310-2/ISO 3310-2, Test sieves Technical requirements and testing Part 2: Test sieves of perforated metal plate. Amdt 1 SANS 197, Preparation of test samples of aggregates. 3 Reagents 3.1 Heavy liquid A liquid that has a relative density

11、(at 24 /24 C) of 2,00 0,01. This liquid may be a solution of zinc chloride in water (the nominal relative density of anhydrous zinc chloride is approximately 2,90), or, alternatively, an appropriate mixture of the compounds listed in table 1. Table 1 Compounds for heavy liquid 1 2 Compound Nominal r

12、elative density Bromoform 2,88 Monobromo-benzene 1,49 SANS 5837:2008 Edition 2.2 2 WARNING The compounds listed in table 1 are highly toxic, both by absorption through the skin and when inhaled. They should only be used in the open air or in a fume cupboard (preferably of the down-draught type) and

13、care should be taken to avoid inhalation and contact with the skin. There is no particular hazard from the zinc chloride solution, but in this case care should also be taken to avoid contact with the eyes and skin. 4 Apparatus Test sieves, of aperture sizes 6,7 mm and 0,150 m, and that comply with t

14、he requirements of SANS 3310-1 or SANS 3310-2. Amdt 1 5 Preparation of test specimens 5.1 Fine aggregate Obtain a test specimen of fine aggregate from the test sample (see SANS 197) of mass approximately 200 g. 5.2 Coarse aggregate Crush a test sample of coarse aggregate (see SANS 197) until it all

15、passes a sieve of aperture size 6,7 mm, and obtain a test specimen of mass approximately 200 g by means of a sample splitter, or by coning and quartering. 6 Procedure 6.1 Dry the test specimen to constant mass at 100 C to 110 C, cool it in a desiccator, and determine its mass to the nearest 0,01 g.

16、6.2 Slowly pour the specimen into approximately 250 mL of the heavy liquid, and decant the supernatant liquid into a beaker through a dry, tared sieve of aperture size 150 m. Ensure that only the floating particles are poured off with the liquid, and that none of the sunken aggregate is decanted ont

17、o the sieve. 6.3 Return the liquid to the beaker containing the aggregate, mix the contents of the beaker by swirling, allow the heavy particles to settle, and decant as in 6.2. 6.4 Repeat this procedure until the supernatant liquid is free from floating particles. 6.5 Wash the decanted particles re

18、tained on the sieve (with water, if a zinc chloride solution was used, and with monobromo-benzene, if an organic heavy liquid was used), dry and cool as in 6.1, and determine their mass to the nearest 0,01 g. SANS 5837:2008 Edition 2.2 3 7 Expression and reporting of results 7.1 Calculate the percentage of materials of low density as follows: 1o 100mmwhere m1is the mass of the decanted particles, in grams; and mois the original mass of the dry specimen, in grams. 7.2 Report the percentage of material of low density to the nearest 0,1 %. Standards South Africa