BS-7976-2-2002.pdf

BRITISH STANDARD BS 7976-2:2002 Pendulum testers Part 2: Method of operation ICS 19.060 ? Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 This British Standard, having been prepared under the direction of the Building Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 20 August 2002 ©BSI 20 August 2002 The following BSI references relate to the work on this British Standard: Committee reference B/556 Draft for comment DC 00/105213 ISBN 0 580 40145 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee B/556, Coordinating pedestrian slip resistance, upon which the following bodies were represented: Association of Consulting Engineers British Ceramic Research Ltd. Department of Transport, Local Government and the Regions represented by the Building Research Establishment Health and Safety Executive Health and Safety Laboratory London Transport RAPRA Technology Ltd. SATRA Technology Centre The Tile Association Co-opted members Contributions are also acknowledged from representatives of the following Technical Committees and Subcommittees: B/505/4/P1, Revision of EN 124 and prEN keys B/507, Paving units and kerbs B/517/8, Protection and repair of concrete structures B/543/6, Timber floors, walls and ceilings B/544/6, Screeds and in situ floorings OC/11, Consumer policy committee PRI/60, Resilient floorcoverings Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 © BSI 20 August 2002 i Contents Page Forewordii 1Scope1 2Normative references1 3Terms, definitions and abbreviations1 4Apparatus1 5Preparation2 6Conducting the test4 7Test report5 8Validation5 9Slider rubber storage/life6 Annex A (normative) Specification for silicon carbide paper7 Annex B (informative) Guidance on sampling7 Bibliography9 Figure 1 Fixing of sheet to plate3 Table 1 Temperature corrections for PTV readings using the TRL rubber slider5 Table 2 Validation PTVs in wet conditions6 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 ii© BSI 20 August 2002 Foreword This part of BS 7976 has been prepared by Technical Committee B/556. BS 7976 has been prepared to meet the need for a definitive method of both operation and calibration of the pendulum tester. This part of BS 7976 specifies a method of operation for the pendulum tester that is specified in BS 7976-1, and should be read in conjunction with BS 7976-1. A method of calibration for this pendulum tester is specified in BS 7976-3. The calibration method specified in BS 7976-3 is applicable for all uses of the pendulum tester. Due to current work being carried out within CEN, and in particular prEN 13036-4, the method of operation specified in this part of BS 7976 is applicable only for the determination of the slip resistance of pedestrian surfaces. However, CEN has recently established a new technical committee to meet the needs of an established test and procedure for the determination of slip/skid, and it is anticipated by Technical Committee B/556 that BS 7976 will form the basis for the work in that forum. The pendulum tester was originally designed by Percy Sigler in the USA in the 1940s to test pedestrian surfaces. It was adopted and further developed in the late 1950s by the then Road Research Laboratory (RRL, now known as the Transport Research Laboratory, TRL). This design has remained basically unchanged to the present day, and other designs based on the same principle are now available. The pendulum tester specified in BS 7976-1 operates on the principle used in the original RRL apparatus. NOTEDetails of the original instrument are given in Road Research Technical Paper No. 66 1. It has been assumed in the preparation of this part of BS 7976 that the execution of its provisions will be entrusted to appropriately qualified and experienced people, for whose use it has been produced. This publication does not purport to include all the necessary provisions of a contract. 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 displayed in this document indicates when the document was last issued. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 © BSI 20 August 2002 1 1 Scope This part of BS 7976 specifies a method of operation of the pendulum tester specified in BS 7976-1. It is applicable only for use in determining the slip resistance of pedestrian surfaces. NOTEThis method of operation is used to determine the pendulum test value. It is also used during calibration, the method of which is specified in BS 7976-3. 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 document (including any amendments) applies. BS 6100-1, Glossary of building and civil engineering terms Part 1: General and miscellaneous. BS 7976-1, Pendulum testers Part 1: Specification. BS EN ISO 4287, Geometrical product specification (GPS) Surface texture Profile method Terms, definitions and surface texture parameters. BS ISO 6344-3, Coated abrasives Grain size analysis Determination of grain size distribution of microgrits P240 to P2500. 3 Terms, definitions and abbreviations 3.1 Terms and definitions For the purposes of this part of BS 7976 the terms and definitions given in BS 6100-1 and the following apply. 3.1.1 swing operation action of raising the pendulum arm so that it engages the release mechanism, then releasing it so that it swings across the surface to be tested 3.2 Abbreviations For the purposes of this part of BS 7976 the abbreviations given in BS 7976-1 and the following apply. 4 Apparatus 4.1 Pendulum tester, conforming to BS 7976-1. 4.2 Thermometer, capable of measuring surface temperatures, accurate to ±0.5?C. 4.3 400 grade silicon carbide resin bonded paper, conforming to Annex A. 4.4 Slider preparation plates (A and B). Each plate shall comprise a piece of hard, flat, reasonably robust, smooth-faced material such as glass or polished metal, and shall have a surface area dimension of not less than 100 mm ? 150 mm. NOTEA plate with larger dimensions is easier to restrain during operation of the pendulum tester. 4.5 3M 261X ImperialTM Lapping Film Grade 3MIC1), or an equivalent product. PTVpendulum test value 1)3M 261X ImperialTM Lapping Film Grade 3MIC is a trade mark owned by 3M United Kingdom plc, P.O. Box 1, 3M House, Market Place, Bracknell, Berkshire RG12 1JU, and is the trade name of a product supplied by: a) Radlett Consultants, 3 Homefield Road, Radlett, Hertfordshire, WD7 8PX; b) RAPRA, Shawbury, Shrewsbury, Shropshire, SY4 4NR; and c) Babtie Group, St Michaels Close, Aylesford, Kent, ME20 7BU. This information is given for the convenience of users of this standard and does not constitute an endorsement by BSI of the product named. Equivalent products may be used if they can be shown to lead to the same results. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 2© BSI 20 August 2002 4.6 Potable water. NOTEFor the method of calibration specified in BS 7976-3, de-ionized or distilled water is used instead of potable water. 4.7 Gauge or graduated scale, in millimetres, for setting the swept length. 5 Preparation 5.1 General 5.1.1 Carry out a visual check of the pendulum tester (4.1) to ensure that it has been assembled correctly and there is no obvious damage that requires repair prior to use. Swing the pendulum arm to see if there are any obvious mechanical defects. 5.1.2 Using the thermometer (4.2), measure and record, to the nearest degree, the temperature of the surface to be tested. 5.1.3 Set the pendulum up over the surface to be tested such that the pendulum swings over the particular area that is required for testing. When testing samples in the laboratory, set the pendulum upon a rigid horizontal surface that includes a suitable means of restraining the test sample. NOTEIf there is any movement between the feet of the pendulum tester and the test surface during a full swing of the pendulum, place weight(s) on the rear leg (ensuring that the base remains level), or use high friction pads under the feet, in order to prevent any such movement. 5.1.4 Whenever the head of the tester is raised or lowered, ensure that the mechanism is firmly clamped afterwards to hold the head securely in position. 5.1.5 Set the pendulum arm in the horizontal position such that it engages the release mechanism. Level the base, using the spirit level and the three levelling screws on the base-frame. Raise the head of the tester such that the pendulum arm swings clear of the surface to be tested. Ensure that the base of the instrument remains stable, relative to the test surface, during a full swing of the pendulum and that neither the arm nor the pointer make contact with any part of the frame, e.g. the scale or the carrying handle. NOTEThe pendulum may be used on a sloping surface (see Annex B) provided that the slope can be accommodated within the adjustment range of the feet. 5.1.6 Check that the slider is correctly fitted to the pendulum and that its working edge is undamaged and the slider is suitably prepared as specified in 5.2 for the type of measurement to be made. NOTECorrect slider preparation is critical for testing smooth floors in wet conditions. 5.1.7 Adjust the zero setting as follows: a) raise the head of the tester to ensure that the slider swings clear of the test surface (see 5.1.4); b) raise the swinging arm to the horizontal release position on the right-hand side of the tester, such that it is locked automatically in the release catch; c) bring the pointer round to its stop in line with the pendulum arm; d) release the pendulum arm; e) catch the pendulum arm on its return swing and record the pointer reading; f) return the pendulum arm to the release position; g) correct the zero setting as necessary by adjustment of the friction rings; h) repeat steps b) to g) until three consecutive zero readings are obtained. NOTEIf the pointer swings past the zero position, screw the rings up a little more tightly. If the pointer does not reach zero, unscrew the rings a little. Ensure that the locking ring is tight before further use. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 © BSI 20 August 2002 3 5.1.8 Set the sliding length of the rubber slider (the distance between two points where the slider edge of the rubber touches the test surface) by gently lowering the pendulum arm until the slider just touches the surface, first on one side of the vertical, and then on the other (see 5.1.4). The sliding length shall be between 125 mm and 127 mm. NOTE 1To facilitate the approximate setting of the sliding length, the spacer provided by the manufacturer may be used. Mount the spacer under the lifting-handle setting screw in order to raise the slider. Lower the head of the instrument such that the slider just touches the test surface across its width. Clamp the head in position and remove the spacer. NOTE 2To prevent undue wear of the slider when moving the pendulum arm through the arc of the contact, raise the slider off the test surface by means of the slider lifting handle. 5.2 Preparation of the slider 5.2.1 General 5.2.1.1 New slider pads shall be prepared in accordance with 5.2.2.1. Worn slider pads shall either be re-prepared in accordance with 5.2.2.2, or discarded in accordance with 5.2.2.3 when they show the amount of wear specified in 5.2.2.3. 5.2.1.2 The rubber shall be free from contamination, e.g. an abrasive, or oil. 5.2.1.3 A sheet of 400 grade silicon carbide resin bonded paper (4.3) shall be fixed to the clean upper surface of plate A (4.4). 5.2.1.4 A sheet of 3M 261X ImperialTM Lapping Film Grade 3MIC or an equivalent product (4.5) shall be fixed to the clean upper surface of plate B (4.4). This sheet shall be secured to the plate along one of its edges only, and such that beyond the fixing the slider pad is able to make contact with at least 127 mm of the attached sheet (see Figure 1). NOTEThe matt surface of the 3M 261X ImperialTM Lapping Film Grade 3MIC is the surface to be used. 5.2.1.5 For each of the procedures specified in 5.2.2.1, 5.2.2.2 and 5.2.2.3, the pendulum tester shall be set up with the slider to be prepared/re-prepared/restored as if to test the slider preparation plates (4.4). The swept length, measured using the gauge or graduated scale (4.7), shall be (126 ± 1) mm (see 5.1.8). 5.2.1.6 The slider preparation plate shall be restrained during the swing operation. Key 1Area of adhesion4Direction of swing 2Slider preparation plate5Swept area 33M 261X ImperialTM Lapping Film Grade 3MIC Figure 1 Fixing of sheet to plate Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:01:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7976-2:2002 4© BSI 20 August 2002 5.2.2 Procedure 5.2.2.1 Preparation of a new slider pad A new slider pad shall be prepared by carrying out 10 swings over plate A, in either wet or dry conditions. For a slider pad of Four-S rubber, to be used to test smooth surfaces (i.e. those with a roughness of less than 15 ?m Rz, as defined in BS EN ISO 4287), further preparation shall be carried out using 20 swings over plate B in wet conditions. 5.2.2.2 Re-preparation of a worn slider pad The working edge of a worn or damaged slider pad shall be re-prepared by carrying out a minimum of three swings across plate A, so that a uniform and smooth working edge to the slider is obtained. For a slider pad of Four-S rubber, to be used to test smooth surfaces (i.e. those with a roughness of less than 15 ?m Rz, as defined in BS EN ISO 4287), further re-preparation shall be carried out using 20 swings over plate B in wet conditions. NOTEIf restoration of the “polish” to the edge of a Four-S rubber slider pad is all that is required, 20 swings across plate B can be sufficient. 5.2.2.3 Discarding worn slide