1、BRITISH STANDARD BS 7932:2003 Determination of the unpolished and polished pendulum test value of surfacing units ICS 93.080.20 BS 7932:2003 This British Standard was published under the authority of the Standards Policy Committee on 28 March 2003 BSI 28 March 2003 First published September 1998 The
2、 following BSI references relate to work on this British Standard Committee reference B/507 Draft for comment 00/107873 DC ISBN 0 580 38096 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee B/507, Paving units and kerbs,
3、upon which the following bodies were represented: Brick Development Association British Cement Association British Ceramic Research Ltd. British Precast Concrete Federation Ltd. Concrete Society County Surveyors Society Department of the Environment, Transport and the Regions (Highways Agency) Insti
4、tution of Civil Engineers Interlay (Association of Block Paving) Interpave (Concrete Block Paving Association) Landscape Institute Society of Chemical Industry Stone Federation Transport Research Laboratory The following bodies were also represented in the drafting of the standard, through Subcommit
5、tee B/507/4, Slip/skid resistance testing: Construction Confederation Consumer Policy Committee of BSI Department of the Environment, Transport and the Regions (Building Research Establishment) RAPRA Technology Ltd. Amendments issued since publication Amd. No. Date CommentsBS 7932:2003 BSI 28 March
6、2003 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative references 1 3T e r m s a n d d e f i n i t i o n s 1 4 Principle 1 5A p p a r a t u s 2 6 Sampling and preparation of test specimens 4 7 Accelerated polishing 4 8P e n d u l u m t e s t 5 9 Test repo
7、rt 6 Annex A (normative) Preparation of the control stone tablets 7 Annex B (normative) Random sampling of surfacing units for testing 8 Bibliography 9 Figure 1 Flat-bed polishing machine 3 Table 1 Grading requirements for corn emery 3BS 7932:2003 ii BSI 28 March 2003 Foreword This British Standard
8、has been prepared by Technical Committee B/507. It supersedes BS 7932:1998 which is withdrawn. In this revision of BS 7932 the size of the test specimen, the width of the rubber slider and the swept length have all been increased. This British Standard calls for the use of substances and/or procedur
9、es that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage. This publication does not purport to include all the necessary provisions of a contract.
10、Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 9 and a back cover. The BSI copyright notice disp
11、layed in this document indicates when the document was last issued.BS 7932:2003 BSI 28 March 2003 1 1 Scope This British Standard describes a test method for determining the unpolished and the polished pendulum test value of surfacing units for pedestrian or traffic purposes, using a flat-bed polish
12、ing machine in conjunction with pendulum test equipment. NOTE The pendulum test values obtained by this test method are used by manufacturers to determine the slip/skid resistance of the surfacing units. 2 Normative references The following referenced documents are indispensable for the application
13、of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS 410-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth. BS 410-2, Test sieves Te
14、chnical requirements and testing Part 2: Test sieves of perforated metal plate. BS 812-103.1, Testing aggregates Part 103: Methods for determination of particle size distribution Section 103.1: Sieve tests. BS 903-A57, Physical testing of rubber Part A57: Determination of indentation hardness by mea
15、ns of pocket hardness meters (ISO 7619). BS 7976-1, Pendulum testers Part 1: Specification. BS 7976-2:2002, Pendulum testers Part 2: Method of operation. BS 7976-3, Pendulum testers Part 3: Method of calibration. 3 Terms and definitions For the purposes of this standard, the following definition app
16、lies. 3.1 surfacing unit single unit of clay, concrete or natural stone used in surfacing pedestrianized and/or trafficked areas 4 Principle The test methodology for determining the unpolished and the polished pendulum test values of surfacing units consists of measuring the pendulum test value of a
17、 surfacing unit before and following the application of an accelerated polishing regime using a flat-bed polishing machine. Measurements are carried out using pendulum test equipment.BS 7932:2003 2 BSI 28 March 2003 5 Apparatus 5.1 Straight-edge. 5.2 Feeler gauge 5.3 Pendulum test equipment, conform
18、ing to BS 7976-1. 5.4 Flat-bed polishing machine, (see Figure 1) consisting of the following: a) a machined, flat circular cast iron or steel grinding plate not less than 600 mm in diameter, which can be rotated in a horizontal plane at a speed of (29 1) r/min; b) a flat, smooth-surfaced styrene but
19、adiene rubber annulus of 600 mm maximum external diameter, approximately 320 mm internal diameter and 5 mm thickness, attached to the upper surface of the grinding plate. NOTE If glue is used to attach the annulus to the grinding plate, care should be taken to ensure it does not affect the hardness
20、of the rubber. The rubber annulus shall have an initial hardness of (69 3) IRHD determined in accordance with BS 903-A57. It shall be stored in the dark at a temperature in the range 5 C to 25 C and shall be conditioned by bringing to a temperature of (30 2) C throughout its mass before attaching to
21、 the grinding plate. After attachment, the grinding plate and annulus shall be kept in the dark at a temperature in the range (20 5) C. The annulus shall not be used after three years from the date of manufacture or after testing 500 specimens, whichever occurs soonest; c) two adjustable metal holde
22、rs, each capable of loosely holding in place a test specimen with dimensions conforming to 6.2 or control stone tablet with dimensions conforming to Annex A. Each metal holder shall allow the test specimens or control stone tablets to be positioned as follows: with the centre points of their outer e
23、dges (270 1) mm from the centre of the grinding plate; diametrically opposite to each other; with their longest sides lying in the direction of rotation of the grinding plate; so as to allow free movement in a vertical plane but be restrained from moving in the horizontal plane; d) a means to ensure
24、 that the required load can be applied evenly to each test specimen, enabling the test specimen and applied weight to move in a vertical direction; e) adjustable weights which permit uniform loading of the test specimen against the surface of the rubber annulus to provide a contact stress (test spec
25、imen plus adjustable weight) of (2 276 10) N/m 2over the area of the test surface; f) separate mechanisms to feed corn emery and emery flour and a means to feed water.BS 7932:2003 BSI 28 March 2003 3 5.5 Polishing media, consisting of the following: a) fresh natural corn emery, of a grading that con
26、forms with Table 1; b) fresh air-floated or water-washed emery flour, which passes a 50 4m test sieve. Polishing media shall be used once only. Table 1 Grading requirements for corn emery Key 1 Sample holder 2S a m p l e 3 Adjustable mass 4W a t e r s u p p l y 5 Emery hoppers with adjustable convey
27、ors 6G r i n d i n g p l a t e 7 Rubber annulus Figure 1 Flat-bed polishing machine Nominal width of sieve aperture Total passing 4m% 600 98 to 100 500 70 to 100 425 30 to 90 355 0 to 30 300 0 to 5 1 2 3 4 5 6 7BS 7932:2003 4 BSI 28 March 2003 6 Sampling and preparation of test specimens 6.1 A sampl
28、e of ten surfacing units shall be obtained in accordance with Annex B, from which four surfacing units shall be selected and prepared for testing in accordance with 6.2, 6.3, 6.4 and 6.5. 6.2 The flatness of the test surface of each test specimen shall be measured using a feeler gauge and a straight
29、-edge across the width of the specimen at a distance approximately 25 mm from either end and at the centre, along the centre of the length and across the two diagonals. The results for flatness shall be recorded. If the deviation from flatness at any point on the test surface of the test specimen is
30、 less than 0.5 mm the surfacing unit shall be tested as a (200 2) mm (100 2) mm test specimen (where a manufactured surfacing unit exceeds this size, it shall be cut to the required dimensions). If the deviation from flatness at any point on the test surface of the test specimen is greater than 0.5
31、mm a test specimen of 140 mm 80 mm, shall be cut. If the dimensions of the manufactured surfacing units are less than 140 mm 80 mm then they shall be glued together to give a test specimen no less than 140 mm to no more than 200 mm long and no less than 80 mm to no more than 100 mm wide. The thickne
32、ss of the test specimens shall not exceed 85 mm. 6.3 The test specimens shall have no transverse or longitudinal warp. If a test specimen has any formed or natural surface features such as ridges, domes, plateaux, channels or cracks, it may either be tested on the reverse surface, providing that the
33、 specimen is of the same material throughout and that the reverse surface does not present any similar surface features, or alternatively if the surface of the specimen contains formed ridges, domes or plateaux greater than 0.5 mm high, these shall be removed by grinding. This shall be noted in the
34、test report. Any formed grooves on a test specimen shall be approximately parallel to the length of the specimen. 6.4 Each specimen shall have a bevel of 2 mm to 3 mm at an angle of approximately 45 along the leading edge, to enable the emery polishing agents to access the contact area between the s
35、pecimens and the rubber annulus more readily. The bevel may comprise the natural chamfer of the surfacing unit or may be specifically ground. NOTE The contact area excludes the bevel or chamfer on the surfacing unit. 6.5 The required load (adjustable weight plus test specimen) necessary to give a co
36、ntact stress of (2 276 10) N/m 2over the area of the test surface shall be calculated. 7 Accelerated polishing 7.1 Procedure WARNING The application of emery polishing agents during the course of the operations described in this clause can generate particles that could be injurious to health. It is
37、essential to ensure that appropriate precautions are taken, e.g. the use of dust masks and/or dust extracting facilities. It is also essential to ensure that the equipment is electrically safe in wet test conditions. 7.1.1 Set up the apparatus as shown in Figure 1 and ensure that the ambient tempera
38、ture is (20 5) C. 7.1.2 Place the test surfaces of two specimens face down in the metal holders of the flat-bed polishing machine according to the configuration given in 5.4c). Apply the appropriate loads calculated in accordance with 6.5. Set the machine in motion at a speed of (29 1) r/min. 7.1.3
39、Feed corn emery of the grading specified in Table 1 evenly onto the surface of the rubber annulus immediately in front of each of the test specimens at a rate of (20 2) g/min, for (700 10) revolutions. Simultaneously feed water onto the surface of the rubber annulus at a rate just sufficient to carr
40、y the corn emery under the test specimens without being washed away. NOTE A water feed rate of 6 ml/min has been found to be satisfactory. 7.1.4 Stop the machine and, within 30 min, remove the test specimens from the machine and remove all traces of corn emery from them under running water using a s
41、tiff-bristled brush. Remove any corn emery from the surface of the rubber annulus. +50 +50BS 7932:2003 BSI 28 March 2003 5 7.1.5 Repeat steps 7.1.2 and 7.1.3, substituting fine emery flour of the grading specified in Table 1 as the polishing agent. Feed the flour at a rate of (2 0.2) g/min evenly ov
42、er the surface of the rubber annulus in front of each of the test specimens with water applied simultaneously at a rate sufficient to maintain a wet paste under the specimens. Polish the specimens for a further (700 10) revolutions. NOTE A water feed rate in the range 1.0 ml/min to 3.0 ml/min has be
43、en found to be satisfactory in maintaining a creamy paste. 7.1.6 Stop the machine, remove the test specimens from the machine within 30 min of the completion of the polishing process and thoroughly wash them in running water to remove all trace of the emery flour. Remove any emery flour which has pa
44、cked into cracks on the surface by scrubbing with a stiff-bristled brush. 7.1.7 After washing the test specimens, store them face downwards under water at a temperature of (20 2) C for at least 2 h to ensure that they are within the temperature tolerance. It is essential not to allow the specimen to
45、 dry out before it is subjected to the pendulum test. 7.1.8 Repeat steps 7.1.2 to 7.1.7 of the procedure for two further test specimens. 7.2 Validation of the accelerated polishing procedure 7.2.1 General In order to maintain the integrity of the polishing procedure, a pair of control stone tablets
46、shall be polished immediately after replacing the rubber annulus see 5.4b) and at a frequency of one pair of control stone tablets every 100 test specimens or once annually, whichever occurs soonest. 7.2.2 Procedure 7.2.2.1 Prepare a pair of control stone tablets in accordance with Annex A. 7.2.2.2
47、Carry out the accelerated polishing procedure on the control stone tablets in accordance with 7.1. 7.2.2.3 Carry out the pendulum test procedure on the control stone tablets in accordance with Clause 8. 7.2.3 Interpretation of results In order for the polishing procedure to be validated, the mean, w
48、ithout rounding, pendulum test value of the two polished control stone tablets shall fall within the range 4955. If the value falls outside this range, the flat-bed polishing machine shall be examined to check whether the feed rate of the grit and water and the hardness of the rubber annulus are cor
49、rect. If they are not correct, the flat-bed polishing machine shall be adjusted and, if necessary, the rubber annulus replaced. 8 Pendulum test 8.1 Validation and calibration of the pendulum test equipment To determine the consistency of readings, the operation of the pendulum test equipment shall be validated in accordance with BS 7976-2:2002, Clause 8. The pendulum test equipment shall have been calibrated in accordance wi
