SANS 5849-2008 Total water-soluble salts content of fines in aggregates《骨料中总水溶性粉状盐的含量》.pdf

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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 978-0-626-21775-4 SANS 5849:2008Edition 2.2Any reference to SABS SM 849 is deemedto be a reference to this standard(Government Notice No. 1373 of 8

4、November 2002)SOUTH AFRICAN NATIONAL STANDARD Total water-soluble salts content of fines in 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 Afric

5、a SANS 5849:2008 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 Committe

6、e StanSA SC 5120.61A, 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 849:2002 (edition 2.1). SANS 5849:2008 Edit

7、ion 2.2 1 Contents Page Foreword 1 Scope and field of application 3 2 Normative references . 3 3 Apparatus . 3 4 Preparation of test specimen . 4 4.1 Fine aggregate 4 4.2 Base-course materials . 4 5 Procedure . 4 5.1 Extraction of water-soluble salts 4 5.2 Recovery of water-soluble salts 5 5.3 Blank

8、 determination . 5 5.4 Expression and reporting of results . 5 SANS 5849:2008 Edition 2.2 2 This page is intentionally left blank SANS 5849:2008 Edition 2.2 3 Total water-soluble salts content of fines in aggregates 1 Scope and field of application This standard specifies a method for determining th

9、e total water-soluble salts content of fine aggregates and of fines in aggregates for base-courses. NOTE Water-soluble salts can be detrimental to roads, to stabilized foundations for paved areas and to concrete. 2 Normative references The following standards contain provisions which, through refere

10、nce 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 are encouraged to take steps to ensure the use of th

11、e most recent editions of the standards indicated below. Information on currently valid national and international standards can be obtained from Standards South Africa. SANS 197, Preparation of test samples of aggregates. SANS 3310-1/ISO 3310-1, Test sieves Technical requirements and testing Part 1

12、: 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 3 Apparatus 3.1 Sieves, that comply with SANS 3310-1 or SANS 3310-2 and of nominal aperture sizes 4,75 mm, 1,70 mm and 425 m. Amdt 1

13、3.2 Mortar and rubber pestle. 3.3 Jar, suitable, sealable, and of capacity about 1L. 3.4 Shaker, mechanical, rotating, and capable of inverting the jar at a rate of 26 to 30 times per minute. 3.5 Witt filter apparatus, fitted with a Buchner funnel of diameter about 90 mm. 3.6 Evaporation dish, of no

14、minal capacity 75 mL, dried at 105 C to 110 C, and tared. SANS 5849:2008 Edition 2.2 4 4 Preparation of test specimen 4.1 Fine aggregate 4.1.1 Dry about 400 g of the test sample (see SANS 197) at a temperature of 80 C 5 C for at least 16 h and then grind it until it all passes a 1,70 mm sieve. By me

15、ans of a sample splitter, or by coning and quartering, obtain a test specimen of mass about 100 g, and grind it until it all passes a 425 m sieve. 4.1.2 Dry the test specimen at a temperature of 80 C 5 C until, after two successive drying periods of 4 h, the decrease in mass does not exceed 0,1 % of

16、 the total mass, and allow it to cool to room temperature in a desiccator. 4.2 Base-course materials 4.2.1 Dry a mass of the test sample (see SANS 197) which is estimated to contain about 400 g of material that passes a 425 m sieve, for at least 16 h at a temperature of 80 C 5 C. Allow to cool, and

17、sieve on a 4,75 mm sieve and a 1,70 mm sieve superimposed on a pan. 4.2.2 Break up any aggregations of smaller particles (taking care not to reduce the size of individual grains) in the portion passing the 4,75 mm sieve and retained on the 1,70 mm sieve by placing it in the mortar and rubbing it wit

18、h the rubber pestle. 4.2.3 Sieve this portion again on the 1,70 mm sieve, add it to the material in the pan, and sieve the mixture on a 425 m sieve. Place the portion on the 425 m sieve in the mortar, rub it as in 4.2.2 above, and again sieve it thoroughly on the 425 m sieve. 4.2.4 Combine the fines

19、 (i.e. all the material that has passed the 425 m sieve) and mix well. By means of a sample splitter, or by coning and quartering, obtain a test specimen of mass about 100 g of the fines, and dry and cool it as in 4.1.2. 5 Procedure NOTE All water used should be distilled or demineralized water. 5.1

20、 Extraction of water-soluble salts 5.1.1 Weigh out 25,00 g 0,01 g (mass b) of the test specimen into a jar (see 3.3) and add exactly 400 mL of water. Stopper the jar and shake continuously for 24 h on the shaker. Remove the jar from the shaker and allow the undissolved material to settle by allowing

21、 the jar to stand undisturbed for at least 1 h. 5.1.2 Place a dry 600 mL beaker in the Witt filter apparatus and a double layer of glass fibre filter paper of fine texture1)on the Buchner funnel, and wet the paper with a few drops of the aqueous extract (see 5.1.1). 5.1.3 Using low vacuum and ensuri

22、ng that the sediment in the flask is not disturbed, filter about 300 mL of the aqueous extract through the filter paper. Then shake the jar vigorously until all the sediment is in suspension and, by rapidly pouring the suspension into the Buchner funnel, attempt to transfer as much as possible of th

23、e undissolved material into the funnel. Wash the residue with 100 mL of water. Complete the filtration by evacuation but do not allow the filter paper to become dry at any time during the whole process. 1) Whatman GF/C or equivalent. SANS 5849:2008 Edition 2.2 5 5.1.4 Transfer the filtrate quantitiv

24、e body to a 500 mL volumetric flask and make up to volume with water. 5.2 Recovery of water-soluble salts 5.2.1 By means of a pipette, transfer 200 mL of the filtrate to a beaker of capacity about 400 mL, boil until the volume of the solution is about 50 mL, and transfer quantitatively to the dry, t

25、ared evaporating dish, washing the beaker three times with warm water and adding the washings to the solution in the evaporating dish. 5.2.2 Evaporate the contents of the evaporating dish to dryness on a water bath, then transfer the dish to an oven maintained at a temperature of 105 C to 110 C and

26、dry for 1 h. Allow the dish and its contents to cool to room temperature in a desiccator, determine the mass, and calculate the mass of the contents of the evaporating dish. 5.3 Blank determination Carry out a blank determination by following the procedures given in 5.1 and 5.2 but omit the 25,00 g

27、of the test specimen. Subtract the mass of any residue found in the evaporating dish from the mass of the contents found in 5.2.2 and record this corrected mass (mass a) as the mass of water-soluble salts in the 200 mL of filtrate. 5.4 Expression and reporting of results 5.4.1 Calculate the water-so

28、luble salts content of the test sample as follows: S = a1010025=bawhere S is the total water-soluble salts content, in percent (by mass); a is the corrected mass of water-soluble salts in the 200 mL aliquot of extract (see 5.3), in grams; and b = 25,00 g, which is the mass of the test specimen (see 5.1.1). 5.4.2 Report the mass percentage water-soluble salts content to the nearest 0,1 %. Standards South Africa