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 978-0-626-19242-6 SANS 794:2009 Edition 2.2 Any reference to SABS 794 is deemed to be a reference to this standard (Government Notice No. 1373 of 8
4、November 2002)SOUTH AFRICAN NATIONAL STANDARD Aggregates of low density Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This standard may only be used and printed by approved subscription a
5、nd freemailing clients of the SABS.SANS 794:2009 Edition 2.2 Table of changes Change No. Date Scope Amdt 1 2002 Amended to update references. Amdt 2 2009 Amended to change the designation of SABS standards to SANS standards, to update the contact details for ASTM, to correct a cross-reference, and t
6、o update referenced standards. Acknowledgement The SABS Standards Division wishes to acknowledge the valuable assistance derived from publications of the following organizations: American Society for Testing and Materials British Standards Institution South African Council for Scientific and Industr
7、ial Research Foreword This South African standard was approved by National Committee SABS SC 59A, Construction standards Cement, lime and concrete, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in Januar
8、y 2009. This document supersedes SABS 794:2002 (edition 2.1). A vertical line in the margin shows where the text has been technically modified by amendment No. 2. This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 1 Conte
9、nts Page Acknowledgement Foreword 1 Scope . 3 2 Definitions 3 3 Physical requirements 4 4 Chemical requirements 5 5 Sampling and compliance with the specification . 6 6 Physical test methods 7 6.1 Bulk density 7 6.2 Grading analysis 8 6.3 Soundness . 8 6.4 Thermal conductivity 11 6.5 Shrinkage . 16
10、7 Chemical test methods 17 7.1 Organic impurities 17 7.2 Sulphur trioxide content . 17 7.3 Sulphide sulphur content . 18 7.4 Loss on ignition 20 7.5 Iron content 20 Annex A Applicable standards . 22 Annex B Notes to purchasers 22 Annex C Bulk densities of aggregates of low density commonly used . 23
11、 Annex D Autoclave: Safety precautions 23 This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 2 This page is intentionally left blank This standard may only be used and printed by approved subscription and freemailing clie
12、nts of the SABS.SANS 794:2009 Edition 2.2 3 Aggregates of low density 1 Scope 1.1 This specification covers inorganic aggregates of low density for use in structural and insulating concretes and in plaster. NOTE 1 The titles of standards referred to by number in the specification are given in annex
13、A. NOTE 2 Requirements that must be specified by the purchaser are listed in annex B. NOTE 3 The bulk densities of aggregates of low density commonly used are given in annex C. NOTE 4 Safety precautions in the use of an autoclave are given in annex D. 2 Definitions For the purposes of this specifica
14、tion the following definitions shall apply: 2.1 aggregate material that is mixed with an inorganic binder to provide the bulk in concrete and plaster 2.2 aggregate of low density aggregate of bulk density not exceeding 1 000 kg/m 32.3 clinker well-burnt furnace residues that have been fused or sinte
15、red into lumps 2.4 coarse aggregate aggregate of which at least 90 % (m/m) is retained on a sieve of nominal square aperture size 4,75 mm 2.5 fine aggregate aggregate of which at least 90 % (m/m) passes through a sieve of nominal square aperture size 4,75 mm 2.6 lot that quantity of fine aggregate o
16、r of coarse aggregate of one nominal size, from one manufacturer, in one vehicle or bin or in one stock pile of not more than approximately 100 m 3submitted at any one time for testing This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:20
17、09 Edition 2.2 4 3 Physical requirements 3.1 Bulk density The bulk density of the aggregate, determined in accordance with 6.1, shall not exceed 1 000 kg/m 3 . 3.2 Grading 3.2.1 Fine aggregates for plaster The grading of fine aggregates for plaster, determined in accordance with 6.2, shall be within
18、 the relevant limits given in table 1. Table 1 Grading of fine aggregates for plaster 1 2 Sieve aperture size* m % (m/m) passing the sieve 4 750 2 360 150 100 90 100 0 10 * Complying with SANS 3310-1 Amdt 13.2.2 Aggregates for insulating concrete The grading of aggregates for insulating concrete, de
19、termined in accordance with 6.2, shall be within the relevant limits given in table 2. Table 2 Grading of aggregates for insulating concrete 1 2 3 Sieve aperture size* % (m/m) passing the sieve mm Fine aggregate Nominal 13,2 mm aggregate 19 13,2 4,75 100 100 100 100 90 100 0 10 2,36 0,150 90 100 0 1
20、0 * Complying with SANS 3310-1 and SANS 3310-2. Amdt 1 This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 5 3.2.3 Aggregates for structural concrete The grading of aggregates for structural concrete, determined in accorda
21、nce with 6.2, shall be within the relevant limits given in table 3. Table 3 Grading of aggregates for structural concrete 1 2 3 4 5 Sieve aperture size* % (m/m) passing the sieve mm Fine aggregate Nominal 13,2 mm aggregate Nominal 19,0 mm aggregate Nominal 26,5 mm aggregate 17,5 26,5 19,0 100 100 85
22、 100 100 85 100 0 50 13,2 9,5 6,70 100 85 100 0 55 0 25 0 50 0 25 0 5 0 25 0 5 4,75 0,150 90 100 0 10 0 10 * Complying with SANS 3310-1 and SANS 3310-2. Amdt 13.3 Soundness Aggregates having a bulk density exceeding 250 kg/m 3shall show no pop-outs when tested in accordance with 6.3.1. In the case o
23、f clinker aggregates the expansion, determined in accordance with 6.3.2, shall not exceed 6 mm. 3.4 Insulating properties of aggregates for insulating plasters and concretes When an aggregate for use in an insulating plaster or concrete is required by the purchaser, the average thermal conductivity
24、at 20 C of the plaster or concrete specimens, determined in accordance with 6.4, shall not exceed the appropriate maximum value given in column 2 of table 4. When the aggregate is to be used in plaster or concrete for use at high temperatures, the average thermal conductivity at 400 C of the specime
25、ns, determined in accordance with 6.4, shall not exceed the appropriate maximum value given in column 3. 3.5 Shrinkage The drying shrinkage of concrete made from aggregate intended for use in structural concrete, determined in accordance with 6.5, shall not exceed 0,06 %. 4 Chemical requirements 4.1
26、 Organic impurities in fine aggregates When tested in accordance with 7.1, fine aggregates shall not generate a colour darker than the standard colour unless it can be proved by compressive strength tests that the discoloration is due to impurities not harmful to concrete or plaster. This standard m
27、ay only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 6 Table 4 Insulating properties 1 2 3 Average thermal conductivity W/(mK), max. Oven-dry bulk density of concrete or plaster specimens kg/m 3At mean temperature 20 C At mean temperature
28、 400 C Up to and including 480 0,115 0,175 Over 480 up to and including 800 0,215 0,300 Over 800 up to and including 1450 0,500 4.2 Sulphur trioxide content The sulphur trioxide (SO 3 ) content of aggregates of bulk density greater than 250 kg/m 3 , determined in accordance with 7.2, shall not excee
29、d 1,0 % (m/m). 4.3 Sulphide sulphur content The sulphide sulphur content of aggregates of bulk density greater than 250 kg/m 3 , determined in accordance with 7.3, shall not exceed 2,0 % (m/m). 4.4 Loss on ignition The loss on ignition of aggregates of bulk density greater than 250 kg/m 3 , determin
30、ed in accordance with 7.4, shall not exceed the following limits, as relevant: a) aggregates other than clinker and clinker for structural concrete, 5,0 % (m/m); and b) clinker for precast masonry units, 25,0 % (m/m). 4.5 Iron content The iron content of aggregates for structural concrete, determine
31、d in accordance with 7.5, shall not exceed 7,5 mg of ferric oxide per kilogram of aggregate. 5 Sampling and compliance with the specification 1)5.1 Sampling The following sampling procedure shall be applied in determining whether a lot complies with the appropriate requirements of the specification.
32、 The sample so drawn shall be deemed to represent the lot. From the lot, draw initial samples as described in table 5. This will give an initial composite sample of about 360 dm 3 . Mix the set of initial samples thoroughly and then by means of a sample splitter reduce the composite sample so obtain
33、ed to a final laboratory sample of about 120 dm 3 . 1) This section applies to the sampling for testing before acceptance or rejection of single lots (consignments) in cases where no information about the implementation of quality control or testing during manufacture is available to help in assessi
34、ng the quality of the lot. It is also used as the procedure for adjudicating in cases of dispute. This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 7 5.2 Compliance with the specification The lot shall be deemed to compl
35、y with the requirements of the specification if, after testing, the final laboratory sample taken in accordance with 5.1 complies with all the appropriate requirements of the specification. 6 Physical test methods 6.1 Bulk density Use a cylindrical metal measure that is rigid enough to maintain its
36、form under rough usage, watertight, and that complies with the requirements given in table 6. Calibrate the measure by determining the mass of water in grams at 20 C required to so fill it that no meniscus is present above the rim of the container (M W ). Dry the aggregate at 110 50 C for at least 1
37、2 h and allow it to cool in the laboratory atmosphere. Using a scoop or similar device, fill the appropriate measure to overflowing, the aggregate being discharged from a height not exceeding 50 mm above the top of the measure. Take care to prevent, as far as possible, segregation of the different p
38、article sizes. Use a straight-edge to strike off surplus aggregate level with the top of the measure, ensuring that any slight projections of larger pieces are approximately balanced by the voids below the top of the measure. Do not compact the aggregate in any manner. Determine the net mass in gram
39、s (M A ) of the aggregate in the measure and calculate the bulk density from the formula: W A 3 M 000 1 M kg/m in density Bulk = Table 5 Sampling methods and quantities 1 2 3 Approximate quantity for each initial sample Source from which sample is drawn Method of sampling dm 3Aggregate in stock pile
40、s Take 12 initial samples from different parts of the stock pile, being careful to avoid sampling a segregated area. Samples should not be taken from the surface. 30 Aggregate in bins Take 6 initial samples from the top surface of the bin and 1 initial sample from the discharge chute. Top surface 30
41、, discharge chute 180 Aggregate being loaded or unloaded Take 12 initial samples at approximately equal intervals throughout the loading or unloading operation. 30 Aggregate in vehicles Divide the load into three approximately equal portions. Dig one trench across each of these portions. The bottom
42、of the trench should be at least 300 mm below the surface of the aggregate and approximately 300 mm wide. Take 8 initial samples from equally spaced points along the bottom of each trench. The shovel must be pushed downward into the material and not scraped horizontally along the surface. 15 This st
43、andard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 8 Table 6 1 2 3 4 5 Nominal size of particles of aggregate Nominal capacity Internal diameter Internal depth Minimum thickness of metal mm L mm mm mm Under 4,75 3 150 150 3,0 Ov
44、er 4,75 15 250 280 4,0 6.2 Grading analysis 6.2.1 Fine aggregates Weigh out accurately a sample, dried as in 6.1, in accordance with table 7. Table 7 1 2 Bulk density Mass of test sample kg/m 3g 50 250 251 500 501 750 Over 750 50 150 200 300 Pass the sample successively through the sieves specified
45、in table 1, or 3, as relevant, and complying with SANS 3310-1 and SANS 3310-2, starting with the largest. Where possible use a mechanical shaker and sieve for 5 min. If hand-sieving must be used, shake the sieves with lateral and vertical motions, accompanied by a jarring action, so as to keep the s
46、ample moving continuously over the surface of the sieve. Continue sieving until not more than 1 % (m/m) of the residue passes through a clean sieve in 1 min. Weigh the fraction retained on each sieve and calculate the cumulative percentage passing each sieve. Amdt 1 6.2.2 Coarse aggregate Weigh out
47、accurately a sample, dried as in 6.1, the volume of which is about 3 4 dm 3 . Pass it successively through the sieves specified in table 2 or 3, as relevant, and complying with SANS 3310-1 and SANS 3310-2 starting with the largest. On sieves larger than 4,75 mm the individual pieces may be passed th
48、rough the sieves by hand. Shake the sieves with lateral and vertical motions, accompanied by a jarring action, so as to keep the sample moving continuously over the surface of the sieve. Continue sieving until not more than 1% (m/m) of the residue passes through a clean sieve in 1 min. Weigh the fra
49、ction retained on each sieve and calculate the cumulative percentage passing each sieve. Amdt 1 6.3 Soundness 6.3.1 Test for pop-outs 6.3.1.1 Apparatus a) Moulds. 200 mm 50 mm 50 mm steel moulds. This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 794:2009 Edition 2.2 9 b) Autoclave. The autoclave shall consist of a high-pressure steam boiler equipped with an automatic pressure control and a safety valve set to release at 6 10 %
