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 978-0-626-23625-0 SANS 285:2010Edition 3.1Any reference to SABS 285 is deemedto be reference to this standard(Government Notice No. 1373 of 8 Novemb
4、er 2002)SOUTH AFRICAN NATIONAL STANDARD Calcium silicate masonry units Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 285:2010 Edition 3.1 Table of changes Change No. Date Scope Amdt 1
5、 2010 Amended to change the designation from SABS to SANS, to update referenced standards and the definition of “acceptable”, and to delete reference to the certification mark from the text. Foreword This South African standard was approved by National Committee SABS TC 59, Construction standards, i
6、n accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in March 2010. This document supersedes SABS 285:1994 (edition 3). Annex A forms an integral part of this standard. Annexes B, C and D are for information onl
7、y. A vertical line in the margin shows where the text has been technically modified by amendment No. 1. SANS 285:2010 Edition 3.1 1 Contents Page Foreword 1 Scope 3 2 Normative references 3 3 Definitions . 3 4 Requirements 4 5 Marking . 6 6 Inspection and methods of test 6 6.1 Inspection . 6 6.2 Met
8、hod of taking samples . 6 6.3 Test specimens 7 6.4 Test for dimensions 7 6.5 Compressive strength test 8 6.6 Drying shrinkage test 9 6.7 Efflorescence test . 11 Annex A (normative) Notes to purchasers . 12 Annex B (informative) Quality verification of calcium silicate masonry units 12 Annex C (infor
9、mative) Recommended nominal dimensions of calcium silicate masonry units . 13 Annex D (informative) Bibliography. 13 SANS 285:2010 Edition 3.1 2 This page is intentionally left blank SANS 285:2010 Edition 3.1 3 Calcium silicate masonry units 1 Scope This standard specifies the characteristics of mas
10、onry units of the calcium silicate type for use in masonry walling. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced doc
11、ument (including any amendments) applies. Information on currently valid national and international standards can be obtained from the SABS Standards Division. EN 12878, Pigments for the colouring of building materials based on cement and/or lime Specifications and methods of test. Amdt 1 EN 12390-4
12、, Testing hardened concrete Part 4: Compressive strength Specification for testing machines. Amdt 1 SANS 7500-1/ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system. Amd
13、t 1 3 Definitions For the purposes of this standard, the following definitions apply: 3.1 acceptable acceptable to the authority administering this standard, or to the parties concluding the purchase contract, as relevant Amdt 1 3.2 bed face one of the surfaces (of the unit) that is normally placed
14、horizontally in a wall 3.3 calcium silicate masonry unit unit building unit that consists essentially of an intimate and uniform mixture of siliceous sand and lime, with or without a coarse aggregate, mechanically moulded into a rectangular shape, hardened by the action of saturated steam under pres
15、sure, and with or without hollows, cavities or perforations SANS 285:2010 Edition 3.1 4 3.4 drying shrinkage difference between the length of a specimen that has been saturated with water and its length after drying to a constant length, under specified temperature and humidity conditions and expres
16、sed as a percentage of the dry length 3.5 efflorescence soluble salts that have crystallized on or near the surface of a unit. Efflorescence can occur to the following degrees: a) nil: no perceptible deposit of salts; b) slight: a very thin deposit of salts, just perceptible, or a small amount of sa
17、lt that occurs only on the edges of a unit; c) moderate: a heavier deposit of salts than “slight“, but that has not caused powdering or flaking of the surface; d) heavy: a thick deposit of salts that covers a large area of the unit, but that has not caused powdering or flaking of the surface; and e)
18、 serious: a deposit of salts that has caused powdering or flaking of the surface. 3.6 face unit unit specially made or selected as being acceptable for use without plaster 3.7 face unit aesthetic FUA unit specially made for its aesthetic effect deriving from non-uniformity of the surface of the inte
19、nded exposed face(s) 3.8 frog depression formed in one or both bed faces of a unit, and the total volume of which does not exceed 25 % of the gross volume of the unit 4 Requirements 4.1 Shape, appearance and colour 4.1.1 Shape All units shall be of nominally rectangular shape (except FUA), shall be
20、true to the appropriate acceptable pattern and may be manufactured with or without frogs. They shall be acceptably free from visible defects that could interfere with the proper laying of the units or impair the strength or the stability (or both) of a construction. 4.1.2 Appearance Face units shall
21、 be acceptably free from nodules of lime or from any weatherable nodules, large cracks, surface defects and other defects that could adversely affect their serviceability or strength, and from constituents that could eventually cause disfigurement. SANS 285:2010 Edition 3.1 5 4.1.3 Colour The colour
22、 of the face units shall be as agreed upon (see 5(b) and annex A.2). The manufacturer shall provide three units of the agreed colour to serve as an example of the possible colour variation. Any pigment used shall comply with the relevant requirements of EN 12878. Amdt 1 4.2 Dimensions The work size
23、of a unit, as indicated by the overall length, overall width and overall height, shall be as required and as stated by the manufacturer (see 5(d), annex A and annex C) and the dimensions of a unit, when determined in accordance with 6.4, shall not differ from the stated nominal values by more than t
24、he applicable tolerance given in column 2 of table 1. Table 1 Tolerances on work sizes 1 2 Overall size Tolerance mm Length + 2 4 Width 31) Height 31) In the case of an FUA, the tolerance on the overall width shall be 10 mm.4.3 Compressive strength A unit shall be one of the classes given in column
25、1 of table 2, as required. The average and individual compressive strengths of units, determined in accordance with 6.5, shall be not less than the appropriate values given in columns 2 and 3 respectively, of table 2, appropriate to the class of unit. Table 2 Compressive strength 1 2 3 Nominal compr
26、essive strength MPa Class of unit Average of 12 units Individual units S7 S14 S21 S35 7 14 21 35 5 12 18 32 4.4 Drying shrinkage The average drying shrinkage of units, determined in accordance with 6.6, shall not exceed 0,06 %. SANS 285:2010 Edition 3.1 6 4.5 Efflorescence When units are tested in a
27、ccordance with 6.7, any efflorescence shall not exceed the relevant degree given in column 2 of table 3, appropriate to the intended application of the units (see annex A). Table 3 Degree of efflorescence 1 2 Intended application Degree of efflorescence a) Intended for use on external faces of walls
28、 Nil b) Intended for use in backings for external walls or in internal walls where dampness can occur Slight c) Intended for any other purpose Moderate 5 Marking Each consignment of units shall be accompanied by a despatch note or a consignment note in which the following information is given: a) th
29、e manufacturers name or trade name or trademark; b) in the case of face units, the colour; c) the class of the units; d) the work size of the units; and e) the intended application of the units. 6 Inspection and methods of test 6.1 Inspection Inspect each unit in the sample for compliance with the r
30、equirements of 4.1 and clause 5. 6.2 Method of taking samples 6.2.1 Sampling during loading and unloading Take the required number of units at approximately evenly spaced intervals throughout the loading or unloading operation. 6.2.2 Sampling from a stack or from a vehicle Take the required number o
31、f units from different positions evenly spaced throughout the stack or load, but if this is impracticable, move units from the upper courses and take the units from various positions within the stack or load and, if possible, from the side of the stack or load. SANS 285:2010 Edition 3.1 7 6.3 Test s
32、pecimens To carry out all the tests, at least 24 units are required as set out in (a) to (c) below. After inspecting the units (see 6.1) and measuring 12 units (see 6.4), allocate the 24 units for submission to the remaining tests, as follows: a) compressive strength test (see 6.5): 12; b) drying sh
33、rinkage test (see 6.6): 6; and c) efflorescence test (see 6.7): 6. NOTE The above figures represent the number of units considered necessary to achieve significant test results. Although such test results can serve as guidance in the assessment of quality of the product, a sampling plan agreed upon
34、between the purchaser and the manufacturer should be used to select the required number of samples in cases where a decision is to be made on the acceptance or rejection of a consignment (see annex B). 6.4 Test for dimensions 6.4.1 Apparatus 6.4.1.1 Steel rule, graduated in increments of 1 mm. 6.4.1
35、.2 End stop, that has a vertical plane face. 6.4.2 Preparation of test specimens Knock off any blisters and remove loose particles from the faces of the units (see 6.3). 6.4.3 Procedure Measure, to the nearest 1 mm, the overall length and height of each unit along the appropriate centre-line of each
36、 stretcher face, and the overall width along the transverse centre-line of each bed face (see figure 1), in each case by placing the appropriate face of the unit against the end stop and measuring the distance from the end stop to the opposite face of the unit. Record the mean of each pair of measur
37、ements as the dimensions of the unit. In the case of an FUA, use any suitable method to check for compliance with the tolerance for overall width and measure the overall length and overall height, using the above procedure. Figure 1 Measuring positions SANS 285:2010 Edition 3.1 8 6.5 Compressive str
38、ength test 6.5.1 Apparatus 6.5.1.1 Testing machine, that complies, as regards accuracy and repeatability, with the requirements of SANS 7500-1 for at least a grade B machine, and Amdt 1 a) that complies with the requirements of EN 12390-4, Amdt 1 b) in which the bearing faces of the platens are at l
39、east as large as (and preferably larger than) the bed faces of the unit under test, and do not depart from plane by more than 0,05 mm, and c) that is capable of a rate of loading approximately 15 MPa/min (calculated using the area of the bed face of the unit under test (see 6.5.2). 6.5.1.2 Capping t
40、able, or bench, that has a non-absorbent surface that is plane to within 0,15 mm in 500 mm, is level in two directions at right angles to each other, and is sufficiently rigid and so supported as to prevent it from being measurably deflected during the capping process. 6.5.1.3 Measuring device, capa
41、ble of measuring, to the nearest 0,5 mm, a reduction in the height of the unit under test. 6.5.2 Area of bed face Measure, to the nearest 1 mm, the length and width of the bed faces of each unit. Calculate the overall area of each of these faces, and use the smaller of the two areas for the calculat
42、ion of compressive strength. 6.5.3 Preparation of test specimens Cap each bed face of each unit (see 6.3) in the manner given in 6.5.3.1 to 6.5.3.4. 6.5.3.1 Prepare capping mortar, consisting of one part (by mass) of portland cement to one part (by mass) of calcined gypsum (plaster of Paris), with e
43、nough water to allow the mortar to spread evenly. 6.5.3.2 Completely fill any frog with capping mortar. 6.5.3.3 Coat the surface of the capping table with oil and spread capping mortar on the oiled surface. Place one of the bed faces on the mortar and, while maintaining the vertical faces of the uni
44、t at right angles to the surface of the table, so press the unit down firmly (with a single movement) into the mortar as to ensure that the average thickness of the cap does not exceed 5 mm. Trim the extruded mortar flush with the vertical faces of the unit. NOTE Do not patch caps after they have se
45、t, but remove imperfect caps and replace them with sound ones. 6.5.3.4 As soon as the cap has hardened sufficiently, slide the unit from the surface of the table and repeat the capping process on the opposite face of the unit, ensuring that the two capped faces are parallel to each other by levellin
46、g the hardened capped face in two directions (at right angles to each other) by means of a spirit level. As soon as the second cap has hardened sufficiently, slide the unit from the surface of the table, leave it to stand for 2 h and then, before testing, immerse it for a period of at least 24 h in
47、clean water maintained at a temperature of 22 C to 25 C. 6.5.4 Procedure 6.5.4.1 Test each unit within 5 min of its removal from the water. SANS 285:2010 Edition 3.1 9 6.5.4.2 Wipe the bearing surfaces of the platens of the testing machine clean and remove any loose sand or other material. 6.5.4.3 S
48、o position the unit in the testing machine that it rests on one capped face, with its centre of gravity over the centre of the lower platen of the machine. Do not use packing pieces between units and the platens. 6.5.4.4 Apply a pre-load of 5 kN (without shock). Then adjust the measuring device and
49、increase the load at a uniform rate such that the rate of stress increase is about 15 MPa/min, until the unit fails. 6.5.4.5 Record, in newtons, the maximum failure load. NOTE The maximum failure load is reached when a) no greater load can be sustained by the unit, or b) the height of the unit is reduced by 5 % of its original height, whichever occurs first. 6.5.5 Calculation Calculate, to the nearest 0,01 MPa, the compressive strength of each unit as follows: =FfAcwhere fcis the compressive strength, in megapascals; F is the failure load, in newtons; and A
