Bsi bs en 13036 4 2011 (2013)

BSI Standards PublicationRoad and airfield surface characteristics — Test methods Part 4: Method for measurement of slip/skid resistance of a surface: The pendulum test... This European

BSI Standards Publication

Road and airfield surface characteristics — Test methods

Part 4: Method for measurement of slip/skid resistance of a surface: The pendulum test

National foreword

This British Standard is the UK implementation of EN 13036-4:2011

It supersedes BS EN 13036-4:2003 which is withdrawn

The UK participation in its preparation was entrusted to Technical Committee B/510/5, Surface characteristics

A list of organizations represented on this committee can be obtained

on request to its secretary

This publication does not purport to include all the necessary provisions

of a contract Users are responsible for its correct application

© The British Standards Institution 2013

Published by BSI Standards Limited 2013ISBN 978 0 580 81260 6

Amendments/corrigenda issued since publication

31 March 2013 Correction to supersession details in national

foreword

NORME EUROPÉENNE

EUROPÄISCHE NORM

October 2011

ICS 17.040.20; 93.080.10; 93.120 Supersedes EN 13036-4:2003

English Version

Road and airfield surface characteristics - Test methods - Part 4:

Method for measurement of slip/skid resistance of a surface:

The pendulum test

Caractéristiques de surface des routes et aérodromes -

Méthode d'essai - Partie 4: Méthode d'essai pour mesurer

l'adhérence d'une surface: L'essai au pendule

Oberflächeneigenschaften von Straßen und Flugplätzen - Prüfverfahren - Teil 4: Verfahren zur Messung der Griffigkeit von Oberflächen: Der Pendeltest

This European Standard was approved by CEN on 29 July 2011

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M IT É E U R O P É E N D E N O R M A LIS A T IO N EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2011 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members Ref No EN 13036-4:2011: E

Contents

Foreword 3



1 Scope 4



2 Normative references 4



3 Terms and definitions 4



4 Safety 5



5 Principle 5



6 Test equipment 5



7 Calibration 12



8 Additional items required for testing 12



9 Test measurements 12



9.1 Measurements in the field 12



9.2 Measurements in the laboratory 13



10 Field sampling 13



11 Test procedure 13



12 Calculations 15



13 Precision 16



14 Test report 17



Annex A (normative) Validation and Calibration of the pendulum friction tester 18



A.1 Validation of the performance of the Pendulum Tester 18



A.1.1 General 18



A.1.2 Procedure 18



A.1.3 Checking for error 19



A.2 Preparation of a new slider 19



A.2.1 General 19



A.2.2 Preparation of a new slider 20



A.2.3 Re-preparation of a used slider 20



A.3 Calibration of the pendulum friction tester 20



A.3.1 General 20



A.3.2 Pre-calibration verification 20



A.3.3 Checking/setting the centre of gravity of the pendulum arm and slider assembly 21



A.3.4 Distance of centre of gravity to centre of rotation 22



A.3.5 Checking/setting the effective spring tension 22



A.3.6 Checking/setting the slider force/deflection characteristics 24



A.3.7 Checking/setting the levelness of the frame 27



A.3.8 Final calibration 28



A.3.9 Calibration report and marking (external calibration) 28



Annex B (informative) Details of scales 29



Annex C (informative) Typical test report 31



Bibliography 32



at the latest by February 2012

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights

This document supersedes EN 13036-4:2003

This European Standard is one of a series of standards as listed below:

 EN 13036-1, Road and airfield surface characteristics — Test methods — Part 1: Measurement of pavement surface macrotexture depth using a volumetric patch technique

 CEN/TS 13036-2, Road and airfield surface characteristics — Test methods — Part 2: Assessment of the skid resistance of a road pavement surface by the use of dynamic measuring systems

 EN 13036-3, Road and airfield surface characteristics — Test methods — Part 3: Measurement of pavement surface horizontal drainability

 EN 13036-4, Road and airfield surface characteristics — Test methods — Part 4: Method for measurement of slip/skid resistance of a surface — The pendulum test

 prEN 13036-5, Road longitudinal evenness — Definition (and calculation methods) of the longitudinal evenness indices

 EN 13036-6, Road and airfield surface characteristics — Test methods — Part 6: Measurement of transverse and longitudinal profiles in the evenness and megatexture wavelength ranges

 EN 13036-7, Road and airfield surface characteristics — Test methods — Part 7: Irregularity measurement of pavement courses: the straightedge test

 EN 13036-8, Road and airfield surface characteristics — Test methods — Part 8: Determination of transverse unevenness indices

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom

1 Scope

This European Standard describes a method for determining the slip/skid resistance of a surface using a device which remains stationary at the test location The slip/skid resistance is measured by means of a slider mounted at the end of a pendulum arm

The method provides a measure of the slip/skid resistance properties of a surface either in the field or in the laboratory

This method measures the slip/skid resistance of a small area of a surface (approximately 0,01 m2) This should be considered when deciding its applicability to a surface which may have non-homogeneous surface characteristics, e.g containing ridges or grooves, or is rough textured (exceeding 1,2 mm mean texture depth)

NOTE As the results from this test are taken at one small location, the results cannot be compared with results from devices e.g mobile devices, that measure the slip/skid resistance over a long length of a surface

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

EN 1097-8, Tests for mechanical and physical properties of aggregates — Part 8: Determination of the polished stone value

ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and

100 IRHD)

ISO 4662, Rubber, vulcanized or thermoplastic — Determination of rebound resilience

ISO 7619-1, Rubber, vulcanized or thermoplastic — Determination of indentation hardness — Part 1: Durometer method (Shore hardness)

ISO 7619-2, Rubber, vulcanized or thermoplastic — Determination of indentation hardness — Part 2: IRHD pocket meter method

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply

NOTE 3 Slip/ Skid resistance is not a constant but varies with climate and traffic and the effect of these on the characteristics of the surface material itself

3.2

friction

resistance to relative motion between two bodies in contact The frictional force is the force acting tangentially

in the contact area

3.3

Pendulum Test Value (PTV)

loss of energy as the standard rubber coated slider assembly slides across the test surface and provides a standardised value of skid resistance

3.4

test

procedure to determine the Pendulum Test Value at a single location or for a single sample in the laboratory

In the field a number of tests will be required to determine the slip/skid resistance of an area

6 Test equipment

6.1 The pendulum tester shall consist of the essential features given below and as illustrated in Figure 1

Key

1 pendulum arm

2 mark (in the centre of rotation)

3 release mechanism (knob)

4 frame

5 rear support foot

6 screw for rear support foot

7 spacer of rough adjustment of the sliding length

(optional)

8 levelling screw

9 bottom plate (hinged, optional)

10 slider assembly

11 slider support rod

12 vertical screw (for vertical adjustment)

13 slider lifting handle

Figure 1 — Pendulum Tester

6.1.1 A spring-loaded slider assembly as specified in 6.3 (wide slider assembly) and 6.4 (narrow slider

assembly) It shall be mounted on the end of a pendulum arm so that the sliding edge is (514 ± 6) mm from the axis of rotation

6.1.2 Means for setting the support column of the equipment vertical

NOTE The three leveling screws are normally used, together with the bubble sprit level accurate to within 4’ of arc (0,06º) or 1 in 1 000 however a magnetic 90º engineer’s spirit level with a nominal sensitivity of 62’’ of arc may be used on the vertical central pillar

6.1.3 A frame of sufficient mass to ensure the equipment remains stable during the test

NOTE A mass of the frame of 3,5 kg has been found suitable

6.1.4 Means of raising and lowering the axis of suspension of the pendulum arm so that the slider can:

 swing clear of the surface of the specimen, and

 be set to traverse a surface over a fixed length of (126 ± 1) mm A gauge with this distance marked is required as shown in Figure 2

NOTE The sliding length may be measured on the surface using tapered gauge 126 Alternatively, gauge 124 of thickness (8 ± 0,2) mm may be used to set the sliding length, which has appropriate marks, aligning the marks with the aluminium backing as shown in Figure 2

Dimensions in millimetres

Figure 2a

Figure 2b Key

1 gauge

2 slider

a measured sliding length

b actual sliding length

Figure 2 — Sliding length gauges 6.1.5 Means of holding and releasing the pendulum arm so that it falls freely from a horizontal position 6.1.6 A pointer of nominal length 300 mm, balanced about the axis of suspension, indicating the position of

the pendulum arm throughout its forward swing and moving over the circular scale (unit scale) The mass of the pointer shall be not more than 85 g

6.1.7 The friction in the pointer mechanism shall be adjustable so that, with the pendulum arm swinging

freely from a horizontal position, the outward tip of the pointer may be brought to rest on the forward swing of the arm at a point (10 ± 1) mm below the horizontal This is the 0 reading

6.1.8 A circular scale (unit scale C) as described in Table B.1, calibrated for a nominal sliding length of

126 mm on a flat surface marked from 0 to 150 at intervals of five Tests in this mode of operation give the Pendulum Test Value directly

6.1.9 A circular scale (unit scale F) as described in Table B.2, calibrated for a nominal sliding length of

76 mm sliding length on a flat surface marked from 0 to 1 at intervals of 0,05 units, may also be present This

is used for a number of laboratory tests as described in the relevant Standards The Pendulum Test Value may be estimated by calculation

NOTE In EN 10978-8, the narrow slider and the sliding length of (76±1) mm is used

6.1.10 All bearings and working parts shall be enclosed as far as possible, and all materials used shall be

treated to prevent corrosion under wet conditions

6.2 The mass of the pendulum arm, including the slider assembly, shall be (1,50 ± 0,03) kg The centre of

gravity shall be on the axis of the arm at a distance of (410 ± 5) mm from the axis of rotation

6.3 The wide slider assembly (see Figure 3) shall consist of a rubber pad (76,2 ±0,5) mm wide, (25,4 ±1,0)

mm long (in the direction of swing) and (6,35 ±0,50) mm thick and an aluminium backing The combined mass

of slider assembly shall be (32 ±5) g

6.4 The narrow slider shall consist of a rubber pad (31,75 ± 0,50) mm wide, (25,4 ± 1,0) mm long (in the direction of swing) and (6,35 ± 0,50) mm thick and an aluminium backing The combined mass of slider assembly shall be (20 ± 5) g

6.5 The rubber pad shall be attached to the aluminium backing by vulcanisation or using adhesive which

does not affect the rubber properties The thickness of the rubber slider including the aluminium backing shall

be in between 9,5 mm and 10,0 mm

6.6 The slider assembly shall be provided with a central pivoting axis which shall be mounted on the end of

the pendulum arm in such a way that, when the arm is at the lowest point of its swing with the trailing edge of the slider rubber in contact with the test surface, the plane of the slider is angled at (26 ± 3)º to the horizontal

In this configuration the slider can turn about its axis without obstruction to follow unevenness of the surface of the test surface as the pendulum swings

6.7 The slider assembly shall be spring-loaded against the test surface The static force on the slider as set

by the equipment calibration procedure shall be (22,2 ± 0,5) N when deflected 4,5 mm measured upside down (see A.3.5) The change in the static force on the slider shall be not greater than 0,2 N/mm deflection of the slider (see A.3.6)

Key

1 rubber pad

2 aluminium backing

3 striking edge

4 worn edge width

Figure 3 — Slider assembly (3D and profile), also illustrating the worn width of the striking edge 6.8 Two different types of slider rubber can be used regarding to the kind of testing The sliders are named

according to the hardness of rubber, slider 57 and slider 96 The initial resilience of the rubber pad shall be measured in accordance with ISO 4662 [using the Lüpke Rebound Hammer]; the hardness of the rubber

pad(compound) shall be measured by the International Hardness Rubber Degrees (IRHD) in accordance with ISO 48 and ISO 7619-2 and the hardness of the rubber on the aluminium backing (complete pad) shall be measured by the Durometer-method (Shore A Hardness) in accordance with ISO 7619-1 The tests on the rubber pad shall be carried out on specimens made up of the same batch of rubber as the relevant pad The results shall comply with Table 1 for slider 57 and Table 2 for slider 96 The manufacturer shall declare the measured resilience of the rubber pad, the measured IRHD values and the values of the Shore A hardness on the pad

6.9 The hardness of the slider shall be checked after receiving from the manufacturer and at least once a

year using a Shore A durometer according to ISO 7619-1 The shore A hardness of a new slider shall not differ more than 3 units from the value of shore A hardness of the slider declared by the manufacturer A slider shall be discarded when the value of the shore A hardness differs by more than two units from the value of shore A hardness measured on the new slider after receiving from the manufacturer

NOTE 1 Slider 57 is normally used for surfaces subject to vehicular traffic For surfaces subject to shoe or foot usage,

as detailed in the relevant standards, slider 96 may be required; this is a harder rubber

Table 1 — Properties of the slider 57

NOTE 2 Sliders 57 are supplied by Federal Institute for Material Research and Testing (BAM), Unter den

Eichen 87, 12205 Berlin, Germany, T: +49 30 8104 2358, F: +49 30 8104 2147, E: webshop@bam.de, I:

www.webshop.bam.de and by Smithers Rapra Technology LTD, Shawbury, Shrewsbury, Shropshire SY4

4NR United Kingdom: T; +44 (0) 1939 250383, F: +44 (0) 1939 251118, E: info@rapra.net, I: www.rapra.net

This information is given for the convenience of users of this European Standard and does not constitute an

endorsement by CEN of the product named Equivalent products may be used if they can be shown to lead to

the same results

NOTE 3 Sliders 96 are supplied by Smithers Rapra Technology LTD, Shawbury, Shrewsbury, Shropshire SY4 4NR

United Kingdom: T; +44 (0) 1939 250383, F: +44 (0) 1939 251118, E: info@rapra.net, I: www.rapra.net.This information

isgiven for the convenience of users of this European Standard and does not constitute an endorsement by

CEN ofthe product named Equivalent products may be used if they canbe shown to lead to the same results

6.10 The slider shall have a certificate of conformity including the name of the manufacturer, date of

manufacture and the measured results of resilience and hardness (IRHD and Shore A)

6.11 The edges of the slider rubber shall be square and clean-cut The rubber shall be free from

contamination by, for example, dust, abrasive or oil

6.12 Before using a new slider rubber it shall be conditioned to achieve a minimum width of sliding edge as

shown in Figure 3 After the conditioning procedure this is typically greater than 1 mm

6.13 This can be achieved by setting up the tester and carrying out sufficient swings wet or dry as described

in A.2

6.14 When the width of the working edge of the rubber pad exceeds 2,5 mm for slider 57 and 3 mm for slider

96, or when it becomes excessively scored or burred, this edge shall no longer be used The edge shall be

suitably disfigured to prevent its further use, and the other long edge of the rubber pad shall be adopted as the

working edge When the width of this edge also exceeds 2,5 mm or 3 mm respectively or when it becomes

excessively scored or burred, the rubber pad shall be discarded

6.15 The slider assembly shall be stored in a dry watertight bag in the dark at a temperature of (10 ± 5) °C

The slider assembly shall be at ambient temperature when used

7 Calibration

7.1 The apparatus shall be calibrated after manufacture and recalibrated at least annually and when

verification demonstrates non-conformity This shall be done by an approved calibration body or part of the organisations certificated quality assurance system

7.2 Calibration procedure is described in Annex A.3

7.3 The calibration procedure shall include at least 3 reference surfaces covering the working range of the

tester

7.4 In addition the validation procedure described in Annex A shall be carried out prior to and following use

for testing

NOTE In this context use for testing is defined as consecutive measurements during one test series during a day

8 Additional items required for testing

8.1 Sufficient clean water in a container for wetting the surface and slider for all the testing required A

separate dispenser may also be required

8.2 Radiation thermometer (pyrometer), or electronic thermometer with a surface probe, with an accuracy of

9.1 Measurements in the field

9.1.1 The test surface shall be brushed free of loose particles and flushed clean with water, unless the test

is to include for the contamination of the surface

9.1.2 Place the Pendulum Tester upon a firm surface with the pendulum swinging in the direction of traffic

The surface shall not have gradient in excess of 10 % Where this is not possible, the test may be carried out

at any angle to the direction of traffic to enable the gradient criterion to be satisfied On surfaces bearing a regular pattern such as ridged or brushed concrete, grooved asphalt or paving blocks, tests should be made with the slider operating at an angle of approximately 80° to the ridges, grooves or joints in pavers

9.1.3 Measure and note the temperature of the test surface and the slider to the nearest whole number The

test cannot be carried out if the temperature of the wet surface and/or slider temperature are outside the range

5 °C to 40 °C

9.1.4 Measure and note the temperature of the water used for wetting the surface to the nearest whole

number The test cannot be carried out if the water temperature differs more than 15 °C from air temperature

9.1.5 Wherever possible the readings shall be taken on the C scale using the wide slider This determines

the PTV directly On non-homogeneous surfaces where a plane test surface can only be achieved of sufficient size to use the narrow slider, this may be used reading on the F scale An estimation of the PTV can be obtained by calculation (See also 12.5 NOTE 1)

9.2 Measurements in the laboratory

9.2.1 Flat laboratory test specimens shall have minimum dimensions of not less than 100 mm × 150 mm

Where the specimens are initially smaller then this specimens may be cut and glued together on a backing panel to provide a plane surface of sufficient size to test Curved specimens for the Polished Stone Value test shall have a test surface as described in EN 1097-8

9.2.2 The appropriate slider assembly with either a slider 57 or slider 96 shall be selected as required 9.2.3 Specimens cut from a surface shall use a method of cutting or coring to ensure the surface to be

tested remains undamaged

9.2.4 Specimens manufactured in the laboratory shall have the texture and material type on the surface

specified in the relevant European Standard or as specifically detailed

NOTE Specimens may be tested as taken from the site, as prepared in the laboratory (unpolished) or after a polishing regime

9.2.5 Laboratory specimens shall be clean and free from contamination or loose particles and held rigidly so

as not to be moved by the passage of the slider

9.2.6 The water for wetting the surface, the pendulum tester, and the slider shall be kept in a room where

the temperature is controlled at (20 ± 2) °C for at least two hours before the test begins and for the duration of the test

9.2.7 Laboratory tests shall be carried out with the specimens held for a minimum of 30 min at (20 ± 2) °C

before testing and for the duration of the test

10 Field sampling

10.1 The slip/skid resistance of some materials varies considerably across/along the area of the surface

Tests shall be taken in the most heavily used area, e.g the wheel track of a road, but other areas may also require testing

10.2 The location and frequency of the testing shall be selected to be representative of the relevant part of

the surface or surfacing materials to be tested

NOTE 1 A sample plan may be necessary to detail where tests should be carried out or afterwards where they have been carried out

NOTE 2 The scope of this standard excludes surfaces which have grooves or ridges, e.g tactile paving units or a high texture depth which can arrest the movement of the pendulum and give erroneous results

NOTE 3 On porous surfaces, which drain water very rapidly, it can be difficult to apply and retain sufficient water on the surface to ensure that the slider rubber is traversing a wet surface throughout the swept length and if this is not possible the test will give erroneous results

10.3 A minimum of three test locations shall be selected These should be measured not more than 400 mm

apart to obtain the mean value for a location The number of tests necessary to obtain the Pendulum Test Value of an area will be dependent upon the variability of the surface

11 Test procedure

11.1 The pendulum test equipment shall be transported in the box supplied with the equipment Carry out a

visual check of the pendulum tester 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 Prior to and after testing the operation of the pendulum shall be validated in accordance with Annex A.1

11.2 The appropriate slider assembly with either slider 57 or slider 96 shall be selected as required

11.3 Ensure that the slider satisfies the requirements of 6.11, 6.12, 6.14 and 6.15 before commencing work

NOTE If the slider assembly has previously been used on a contaminated surface, the subsequent test result may be affected The slider rubber should be reconditioned by carrying out three swings over the wetted conditioning surface as described in Annex A.1

11.4 In the field, check the surface temperature when wet at each test location If a pyrometer is used to

measure the slider surface temperature it shall be orientated perpendicular to the direction of the surface

11.5 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 surface that includes a suitable means of restraining the test sample in a horizontal position and support it solidly The adjustable feet are used in conjunction with the built-in spirit level to ensure that the frame of the instrument is horizontal It is important that the bubble lies exactly in the centre of the spirit level

11.6 Raise the axis of suspension of the pendulum so that the arm swings freely, and adjust the friction in

the pointer mechanism so that when the pendulum arm is released from the right-hand horizontal position the pointer comes to rest at zero position on the test scale Repeat twice more for confirmation If 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

NOTE 1 If there is any movement between the feet of the pendulum tester and the test surface during a full swing of the pendulum, weight(s) should be placed on the rear leg (ensuring that the frame remains level), or high friction pads under the bottom plates should be used, in order to prevent any such movement

NOTE 2 The check required by Paragraph 11.6 ensures that the tester is still functioning properly This adjustment is necessary when the tester is used under different temperature conditions

NOTE 3 Some difficulty may be experienced in the field in strong winds, in excess of about 10 m/s, in which case the test may be aborted It may be necessary to screen the pendulum for gusts created by passing traffic

11.7 Adjust the height of the pendulum arm so that in traversing the surface the slider is in contact with it over

the whole width of the slider and over the length below using the procedure in 11.8 A pre-marked gauge shall

be used as shown in Figure 2 Wet the surfaces of the specimen and the slider rubber with a copious supply

of water

11.8 Set the sliding length of the slider (the distance between two points where the sliding edge of the rubber touches the test surface) by gently lowering the pendulum arm while using the vertical screw (Figure 1) after unclamp the head of the pendulum until the slider just touches the surface, first on one side of the vertical, and then on the other.The sliding length shall be between (126 ± 1) mm for the wide slider and (76 ± 1) mm for the narrow slider This is normally accomplished as follows in a series of small steps, using one of the gauges shown in Figure 2 for 126 mm sliding length or a special scale for the narrow slider with a sliding length of 76mm

11.8.1 Move the pendulum foot to the right and lower the head so that the slider starts to contact the test

surface with its rear corner (aluminium backing) level with the right (outermost) mark on the gauge Manually hold the gauge in that position

11.8.2 Raise the slider with the slider lifting handle and move the pendulum foot to left hand side sufficiently

to ensure the slider is clear of the surface when the slider is lowered

11.8.3 Allow the pendulum foot to gently drop back so that the slider contacts the test surface

11.8.4 The rear edge (aluminium backing) of the slider shall coincide with the left hand mark of the gauge If

not, then raise or lower the Pendulum head so that the slider moves about 50 % of the distance towards the

correct setting

11.8.5 Reclamp the head, reposition the gauge so that the corner of the slider is level with the left

handgauge mark and then move the pendulum foot over to the right hand side and check if it lines up with the

righthand gauge mark If not, repeat the process, backwards and forwards until the pendulum head is set at

the correct height to give the required sliding length Alternatively use a gauge or scale and measure directly

at the contact points of rubber and test surface If the sliding length is okay return the pendulum arm to its rest

horizontal position (in the release catch)

11.9 Wet the surfaces of the specimen and the slider rubber with a copious supply of water, being careful not

to disturb the slider from its set position

NOTE On surfaces typical of those found on roads, at least 100 ml of water may be required to be applied to the

surface and the slider rewetted prior to each swing to ensure the wet slider is passing over the wet test surface Applying

too little water will have a significant effect on the results if any part of the swept length is dry

11.10 Release the pendulum arm and pointer from the horizontal position using the release mechanism

(knob), catch the pendulum arm on the early portion of the return swing and record the position of the pointer

on the scale to the nearest whole number Return the pendulum arm by raising the slider using the lifting

handle and pointer to the release position

11.11 Perform this operation five times, re-wetting the surface and slider copiously just before releasing the

pendulum and recording the result each time If the first five readings differ by more than three units, repeat

until three successive readings are constant and record this value

NOTE 1 It is important that when reading the position of the pointer on the scale that the eye is positioned in a line with

the Mark (in the centre of rotation) – Figure 1, Key 2 – and the end of the pointer on the scale to avoid erroneous readings

NOTE 2 Some product test methods use a different number of swings and a different calculation of the PTV

11.12 In the field, recheck the slider contact length and recheck the temperature of the wetted surface and

the slider rubber on completion of the test

11.13 On completion of testing, check the equipment is still level and swing the pendulum as described in

11.6 to ensure there has been no disturbance during testing If this is apparent, discard the results and repeat

vj is the constant value achieved by the final three swings if the initial swings are too variable as

described in 11.11

NOTE Some product test methods use a different number of swings and a different calculation of the PTV

12.2 Report the PTV to the nearest whole number

12.3 Where testing in the field, correct Pendulum Test Value for temperature using the nearest temperature

from Table 3 below

12.4 The measured slider temperature shall be the mean of the temperatures of the wetted slider before and

after testing

12.5 Report the temperature corrected PTV value as PTVCorrto the nearest whole number

The PTV for a location is the mean of three individual PTV determinations

NOTE 1 Where it was not possible to use the wide slider, the results for a narrow slider (see 6.4) on a flat

surface/specimen over a 76 mm nominal swept length, shall be multiplied by a factor of 1,1 to obtain an estimated PTV

within 10 %

Table 3 — Correction of PTV when the test is carried out at other than 20 °C using slider 57

Measured slider temperature

°C Correction to measured value

NOTE The temperature correction can be affected by the texture of the surface

NOTE 2 The temperature correction for slider temperatures above 30 °C and below 10 °C are approximate and depend upon the roughness of the surface being tested

No temperature correction of Pendulum Test Value (PTV) is required when the test is carried out at other than

20 °C using slider 96

13 Precision

The reproducibility of the measuring method has been examined on the basis of a round-robin test in which eleven different European laboratories participated This involved testing twelve different material surfaces, whereby each laboratory tested the relevant material surfaces under laboratory conditions, using a slider 57

as well as a slider 96 Testing was done in the “wet” condition The materials were tested in two opposite directions and the average value was examined The standard deviations found were as follows:

 Slider 96: From 1.5 to 4.5 PTV units, depending on the nature and the surface characteristics of the material, with an average standard deviation of 2.4 PTV units