prEN 13036-4

SLOVENSKI STANDARD
01-marec-2026
Značilnosti cestnih in letaliških površin - Preskusne metode - 4. del: Metoda
merjenja odpornosti površine proti drsenju/zdrsu - Preskus z nihalom
Road and airfield surface characteristics - Test methods - Part 4: Method for
measurement of slip/skid resistance of a surface: The pendulum test
Oberflächeneigenschaften von Straßen und Flugplätzen - Prüfverfahren - Teil 4:
Verfahren zur Messung der Griffigkeit von Oberflächen: Der Pendeltest
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
Ta slovenski standard je istoveten z: prEN 13036-4
ICS:
17.040.20 Lastnosti površin Properties of surfaces
93.080.10 Gradnja cest Road construction
93.120 Gradnja letališč Construction of airports
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 17.040.20; 93.080.10; 93.120 Will supersede EN 13036-4:2011
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 - Oberflächeneigenschaften von Straßen und
Méthode d'essai - Partie 4: Méthode d'essai pour Flugplätzen - Prüfverfahren - Teil 4: Verfahren zur
mesurer l'adhérence d'une surface: L'essai au pendule Messung der Griffigkeit von Oberflächen: Der
Pendeltest
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 227.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13036-4:2026 E
worldwide for CEN national Members.

Contents Page
European 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 . 10
8 Additional items required for testing . 10
9 Test measurements . 11
9.1 Measurements in the field . 11
9.2 Measurements in the laboratory . 11
10 Field sampling . 12
11 Test procedure . 12
12 Calculations . 14
12.1 Calculate the Pendulum Test Value as the mean of the last five swings using the
formula . 14
13 Precision . 15
14 Test report . 16
Annex A (normative) Validation and Calibration of the pendulum friction tester . 18
Annex B (informative) Details of scales . 30
Annex C (informative) Typical test report . 32
Bibliography . 34
European foreword
This document (prEN 13036-4:2026) has been prepared by Technical Committee CEN/TC 227 “Road
Materials”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13036-4:2011.
EN 13036-4:2026 includes the following significant technical changes with respect to EN 13036-4:2011:
— Sliders characteristics (see Clause 6.9);
— Test procedure (see Clause 11.7);
— Temperature correction (see Clause 12.5).
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
EU Directive(s) / Regulation(s).
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
— EN 13036-5, Road and airfield surface characteristics - Test methods - Part 5: Determination of
longitudinal unevenness 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
1 Scope
This document 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 wetted 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 m ). It is
important to consider this when deciding its applicability to a surface which might have
nonhomogeneous surface characteristics, e.g. containing ridges or grooves, or is rough textured
(exceeding 1,5 mm mean texture depth).
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.
ISO 4662, Rubber, vulcanized or thermoplastic — Determination of rebound resilience
ISO 48-2, Rubber, vulcanized or thermoplastic — Determination of hardness — Part 2: Hardness between
10 IRHD and 100 IRHD
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
skid resistance
property of the trafficked surface which limits the relative movement between the contact patch of a
vehicle tyre and the surface
Note to entry 1 Loss of skid resistance leads to loss of control by the driver with consequent increase in the risk of
crashes.
Note to entry 2 There are numerous factors which contribute to skid resistance, including the tyre pressure,
contact area, tread pattern and rubber composition of the tyre or sole; the alignment, texture and frictional
characteristics of the surface; the vehicle speed; the weather conditions, i.e. wet/dry and presence of surface
contamination.
Note to entry 3 Skid resistance is not a constant but varies with climate and traffic which affect the characteristics
of the surface material itself.
3.2
slip resistance
contribution of the surface to the generation of friction force resulting from the interaction between
pedestrian footwear and a surface
3.3
friction
force resisting to relative motion between two bodies in contact
Note to entry 1 The frictional force is the force acting tangentially in the contact area
3.4
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 by isolating the contribution of the surface to the friction
generated between the slider assembly and surface
3.5
test
procedure to determine the Pendulum Test Value at a single location or for a single sample in the
laboratory
Note to entry 1 In the field a number of tests will be required to determine the slip/skid resistance of an area
4 Safety
When carrying out the test in the field, the equipment and operator will form a stationary obstruction.
Adequate safety measures shall be in place to maintain a safe working area in accordance with
regulations.
5 Principle
The Pendulum Tester incorporates a spring-loaded slider made of a standard rubber mounted to the end
of a pendulum arm. Upon releasing the pendulum arm from a horizontal position, the loss of energy as
the slider assembly passes over the test surface is measured by the reduction in length of the upswing
using a calibrated scale.
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 15 clamp for vertical adjustment
2 mark (in the centre of rotation) 16 spirit level
3 release mechanism (knob) 17 gauge (see Figure 2)
4 frame 18 pendulum foot
5 rear support foot 19 friction ring (including locking ring)
6 screw for rear support foot 20 pointer
7 spacer of rough adjustment of the sliding length 21 pointer counterbalance
(optional)
8 levelling screw 22 unit scale
9 bottom plate (hinged, optional) 23 unit scale F (optional)
10 slider assembly 24 unit scale C
11 slider support rod 25 release catch
12 vertical screw (for vertical adjustment) 26 pointer cam (calibration purpose:
pointer adjustment screw)
13 slider lifting handle 27 handle
14 pendulum head 28 lock nut
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 levelling screws are normally used, together with the bubble spirit level accurate to within 4’
of arc (0,06°) or 1 in 1 000 however a magnetic 90° engineer’s spirit level with a nominal sensitivity of 62” of arc
can 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 can be measured on the surface using the tapered gauge 126. Alternatively, gauge 124
of thickness (8 ± 0,2) mm can be used to set the sliding length, which has appropriate marks, aligning the marks
with the aluminium backing as shown in Figure 2a.
Dimensions in millimetres
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.1, 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 or from 0 to 100 at
intervals of 5, 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 1097-8, 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)° 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 (compound) shall be measured in accordance with ISO 4662. The hardness of the rubber pad
(compound) shall be measured by the International Rubber Hardness Degree (IRHD) in accordance with
ISO 48-2 (slider 57: method N; slider 96: method H and N (for information)). The hardness of the rubber
on the aluminium backing (complete slider) shall be measured by the Durometer-method (slider 57:
Shore A Hardness; slider 96: Shore D Hardness) in accordance with ISO 48-2. The tests on the rubber pad
shall be carried out on specimens made up of the same batch of rubber as the relevant pad on the slider.
The results shall comply with the Table 1 for slider 57 and Table 2 for slider 96. The manufacturer shall
declare the measured resilience, the measured IRHD (method N or method H) values of the rubber pad
(compound) and the values of the Shore A or Shore D hardness on complete slider.
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 48-2. 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 same slider after receiving from the manufacturer.
The testing of the shore hardness shall be done at 20 ± 2 °C.
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
Temperature
°C
Property
0 10 23 30 40
Resilience, % 43 to 49 58 to 65 66 to 73 71 to 77 74 to 79
Hardness, IRHD N 55 to 61
Table 2 — Properties of the slider 96
Temperature
°C
Property
5 23 40
Resilience, % 19 to 23 21 to 26 26 to 30
Hardness, IRHD N 94 to 98
Hardness, IRHD H 94 to 98
6.10 The slider shall have a certificate of conformity including the name of the manufacturer, date of
manufacture and the measured results of initial resilience and hardness (IRHD and Shore A), including
the relevant test conditions, such as temperature.
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 visibly damaged, 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 visibly damaged, 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 between
4 °C and 10 °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 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 ± 0.5 °C for measuring the test surface.
8.3 Spirit level at least 1 m long and steel tape accurate to 1 mm or other device for measuring gradient.
8.4 A stiff non-metallic hand brush for cleaning the surface (if required).
8.5 A portable anemometer accurate to 2 m/s for field use (optional).
8.6 An electronic thermometer with an accuracy of ± 0.5 °C for measuring the water temperature and
air temperature.
9 Test measurements
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 transverse
ridges, grooves or joints in pavers and approximately 10° to longitudinal grooves or joints.
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 and the air
temperature 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 x 150 mm. Where the specimens are initially smaller than these dimensions, they may be cut and
glued together on a backing panel to provide a plane surface of sufficient size to test.
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 can 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.
A sample plan may be necessary to detail where tests should be carried out or afterwards where they
have been carried out.
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 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
the work.
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 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.
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 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.
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 of wind.
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
100 ± 20 ml 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. After unclamping the head of the
pendulum, use the vertical screw (Figure 1) to lower the pendulum arm 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 hand
gauge 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 by using 100 ml of water, being careful not
to disturb the pendulum from its test position.
On surfaces typical of those found on roads, 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 just before releasing the
pendulum and recording the result each time. If the first five readings differ by more than three units
using the C scale (or 0.05 using the 0 to 1 F scale) repeat until three successive attempts yield readings
that differ by no more than 3 units using the C scale or 0.05 using the F-scale. Record the values of all
attempts.
NOTE When reading the position of the pointer on the scale it is important to take care to avoid erroneous
readings due to parallax.
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 the test.
11.14 Carry out the required number of tests as described in 10.3.
12 Calculations
12.1 Calculate the Pendulum Test Value as the mean of the last five swings using the
formula
∑ vvv+ ++ v + v
( )
1 2 3 4 5
PTV=
(1)
Where
v1 to v5 are individual values for each swing
or
PTV = v (2)
j
Where
v the constant value achieved by the final three swings if the initial swings are too
j
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 When 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 PTV to the nearest whole number.
Corr
The PTV for a location is the mean of three individual PTV determinations.
When 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
39–40 +9
37–38 +8
35–36 +7
33–34 +6
30–32 +5
28–29 +4
26–27 +3
24–25 +2
22–23 +1
19–21 0
17–18 −1
15–16 −2
13–14 −3
11–12 −4
8–10 −5
6–7 −6
5 −7
No temperature correction shall be applied on measurement results on smooth surfaces, i.e. surfaces
lacking any visible macrotexture
NOTE Temperature corrections are influenced by the macrotexture and the more the temperature deviates
from the reference temperature 20°C, the larger the uncertainty on the correction.
Corrections for measurements carried out at temperatures outside the range 13°C - 27°C should rather
be considered as estimations
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.
— Slider 57: From 1.4 to 3.9 PTV units, depending on the nature and the surface characteristics of the
material, with an average standard deviation of 2.6 PTV units.
14 Test report
14.1 The field test report shall include the following information (see Annex C):
a) reference to this document;
b) name of the organization carrying out the test;
c) name of the person carrying out the test;
d) time and date of the test;
e) location of the site(s);
f) location of each test (e.g. distance from an edge or other feature and chainage);
g) angle of testing relative to direction of traffic (if not parallel);
h) measured temperature of wet surface and wet slider rubber before and after testing (slider 57 only);
i) whether the slider assembly was wide or narrow;
j) whether slider 57 or slider 96 was used;
k) number of the slider;
l) mean PTV and mean corrected PTV (PTV ) at each test position, and for each area of surface (if
Corr
required);
m) any pertinent remarks about the surface type.
14.2 The laboratory test report shall include the following information:
a) reference to this document;
b) name of the organization carrying out the test;
c) name of the person carrying out the test;
d) time and date of the test;
e) whether the specimen was curved or flat;
f) whether the slider assembly was wide or narrow;
g) whether slider 57 or slider 96 was used;
h) reference number of the slider;
i) mean Pendulum Test Value (PTV) of the specimen;
j) any pertinent remarks about the test specimen.
Annex A
(normative)
Validation and Calibration of the pendulum friction tester
A.1 Validation of the performance of the Pendulum Tester
A.1.1 General
A.1.1.1 To ensure consistency of readings, the operation of the pendulum tester shall be validated
daily, prior to and after use, using the method described below. It should also be used on return from
calibration to check for damage in transit.
A.1.1.2 The validation procedure comprises one set of readings in the wet condition on two standard
surfaces, representing high and low PTV.
A.1.1.3 The standard surfaces shall be of float glass, free from contamination and scratches and a wet
piece of verification film mounted on float glass. The verification film shall be used for one day only.
A.1.1.4 The values obtained shall be used to monitor the performance of the operation of the
pendulum tester until it is next calibrated.
A.1.1.5 The acceptable verification limits are given in Table A.1.
Table A.1 — Verification values for pendulum operation (wet condition)
a
PTV slider 57 PTV slider 96
Float Glass 3 to 8 5 to 10
Reference Tile 13 to 19 31 to 37
Verification Film 47 to 53a 58 to 64
a
If the values with slider 57 are outside the range, the verification may be repeated with slider 96. If this is in
tolerance, the operation of the pendulum has been verified.
A.1.1.6 When conducting the verification test a single virgin/untested area of the sheet of verification
film shall be used for the set of eight swings required.
NOTE The float glass measurement might be influenced by the moisture penetration in the rubber pore
structure. It is important to recondition the rubber slider before verifying the float glass value.
A.1.1.7 Should the value obtained from any daily check vary by more than 4 units from the value
obtained in on return from calibration, the operation of the pendulum tester shall be investigated.
A.1.1.8 Should the value obtained between start and finish checks on any one day vary by more than
2 units, the operation of the pendulum tester shall be investigated.
NOTE The procedure can also be used to ensure that the operative is using the procedures in this document
correctly.
A.1.2 Procedure
A.1.2.1 Before carrying out the validation of performance of the Pendulum Tester, the pendulum
should be adjusted in accordance with Clause 11. The laboratory shall maintain a piece of clean
unscratched float glass for validation testing and for no other purpose. The side tested shall be identified
and used. The size shall be at least 150 mm by 100 mm by 10 mm thick as shown in Figure A.1.
A.1.2.2 The laboratory shall maintain a stock of verification film grade 3 micron, aluminium oxide
abrasive mounted on a waterproof backing film. The verification film shall be mounted on a piece of float
glass used for validation testing. The size shall be at least 200 mm by 150 mm as shown in Figure A.1. The
verification film shall be fixed to the glass using double sided adhesive tape along one edge only. The
taped edge shall be mounted so that during testing it is the leading edge of the test piece. The taped edge
shall not be included within the area swept by the pendulum.
NOTE Pink lapping paper, 261 × Imperial, grade 3 micron, mineral Aluminium Oxide Backing 3 mm which is
available from 3M is suitable as verification film
A.1.2.3 Both the float glass and abrasive surface shall be tested wet at (20 ± 2) °C using the method
described in Clause 11, except that instead of potable water as specified in 8.1, de-ionized or distilled
water shall be used.
Dimensions in millimetres
Key
1 area of adhesion
2 glass plate
3 abrasive paper
4 direction of swing
5 swept area
Figure A.1 — Fixing of sheet to plate
A.1.3 Checking for error
A.1.3.1 After conducting the test, raise the head of the instrum
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