EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
DRAFT prEN 13036-4 September 2009
ICS 93.080.20; 17.040.20
Will supersede EN 13036-4:2003
English Version
Method for measurement of slip/skid resistance of surface - Part 4: The pendulum test Characteristiques de surface Methode d'essai - Methode d'essai pour mesurer l'adherence d'une surface - Partie 4 : L'essai au pendule
Oberflächeneigenschaften-prüfve Oberflächeneigenschaften-prüfverfahren rfahren - Methode zur Messung der Griffigkeit von Oberflächen - Teil 4: 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 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, 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. 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
Management Centre: Avenue Marnix Marnix 17, B-1000 Brussels Brussels
© 2009 CEN
All rights of exploitation exploitation in any form and by any means reserved worldwide for CEN national Members.
Ref. No. prEN 13036-4:2009: E
prEN 13036-4:2009 (E)
Contents
Page
Foreword ....................................................................................................... ..............................................................................................................................................................3 .......................................................3 1
Scope .................................................................................................... ......................................................................................................................................................4 ..................................................4
2
Normative references ............................................................................................................................4 ............................................................................................................................4
3
Terms and definitions definition s ...........................................................................................................................4 ...........................................................................................................................4
4
Safety .............................................................................. .............................................................................................................................................. ........................................................................5 ........5
5
Principle ..................................................................................... ..................................................................................................................................................5 .............................................................5
6
Test equipment ......................................................................................................................................5 ......................................................................................................................................5
7
Calibration ...................................................................................................................... ........................................................................................................................................... ..................... 10
8
Apparatus ....................................................................................................................... ............................................................................................................................................ ..................... 10
9 9.1 9.2
Test Measurements M easurements ............................................................................................................................ ............................................................................................................................ 10 Measurements in the th e field fie ld ..................................................................................................... .................................................................................................................. ............. 10 Measurements in the laboratory ....................................................................................................... 11
10
Field sampling ........................................................................................................... ..................................................................................................................................... .......................... 11
11
Test procedure ................................................................................................................ .................................................................................................................................... .................... 12
12
Calculations .............................................................................................................................. ......................................................................................................................................... ........... 13
13
Precision .............................................................................................................................................. .............................................................................................................................................. 14
14
Test report .................................................................................................... ........................................................................................................................................... ....................................... 14
Annex A.1 A.1.1 A.1.2
A (normative) A (normative) Validation and calibration of the Pendulum Friction Tester ................................... 16 Validation of th e performance o f the pendulum .............................................................................. 16 General ....................................................................................................................... ................................................................................................................................................. .......................... 16 Procedure ....................................................................................................................... ............................................................................................................................................ ..................... 16
Annex B (normative) B (normative) Details of Scales ........................................................................................................ .......................................................................................................... .. 21 Annex C (informative) C (informative) Typical Composition of the CEN Slider Rubber ..................................................... ..................................................... 23
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prEN 13036-4:2009 (E)
Foreword This document (prEN 13036-4:2009) has been prepared by Technical Committee CEN/TC 227 “Road materials”, the secretariat of which is held by DIN. This document is currently submitted to the CEN Enquiry. This document will supersede 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 EN 13036-2, Road and airfield surface characteristics — Test method — Part 2: Procedure for determination of skid resistance of a pavement surface 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 longitudinal evenness — Profilometric test methods EN 13036-7, Road and airfield surface characteristics — Test methods — Part 7: Irregularity measurement of pavement courses — the straightedge test
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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 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 m 2). 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 patch test). NOTE 1 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. NOTE 2 The accuracy and precision of the test can be affected by the operative. The test should be carried out by a trained and competent person who has carried out the validation procedure in Annex A.1.
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 13036-1, Surface characteristics —Test methods — Part 1: Measurement of surface macrotexture depth using a volumetric technique ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (Hardness between 10 IRHD and 100 IRHD) ISO 7619, Rubber — Determination of indentation hardness by means of pocket hardness metres ISO 4662:1986, Rubber — Determination of rebound resilience of vulcanizates
3
Terms and definitions
For the purposes of this document, the following definitions apply. 3.1 slip/skid resistance property of the trafficked surface which limits the relative movement between the contact patch of pedestrian footwear or a vehicle tyre and the surface NOTE 1 Loss of slip/skid resistance leads to loss of control by the pedestrian/driver with consequent increase in the risk of falling/ crashes. NOTE 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. 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.
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3.2 friction resistance to relative motion between two bodies in contact, with the frictional force being the force acting tangentially in the contact area 3.3 pendulum test value ( PTV ) loss of energy measured by the Pendulum Tester as the standard rubber coated slider assembly slides across the test surface and provides a standardised value of skid resistance
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 attached to the end of a pendulum. On releasing the pendulum 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 6.1
Test equipment The pendulum test shall incorporate the essential features given below and as illustrated in Figure 1.
A spring-loaded slider assembly as specified in 6.3. 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.
Means for setting the support column of the equipment vertical.
NOTE 1
Levelling screws with or without a bottom plate are commonly used in conjunction with a spirit level.
A base of sufficient mass to ensure the equipment remains stable during the test.
NOTE 2
A mass of 3,5 kg has been found suitable.
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.
Means of holding and releasing the pendulum arm so that it falls freely from a horizontal position.
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. The mass of the pointer shall be not more than 85 g.
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.
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A circular scale (C scale) as described in Annex B, 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 PTV directly.
A circular scale (F scale) as described in Annex B, 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 PTV may be estimated by calculation.
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.
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Key 1 2 3 4
spirit level levelling screw pointer vertical adjustment screw
5 6 7 8
C unit scale (126 mm sliding length) F unit scale (76 mm sliding length) starting bottom rubber slider
Figure 1 — The pendulum tester
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Key A B C 1 2
side view view in plan gauge side view slider sliding length measured
3 4 5 6
reference edge gauge actual sliding length gauge sickness
Figure 2 — Sliding length gauge
Key 1 2 3 4
striking edge aluminium backing rubber slider worn between 1 mm and 3 mm Figure 3 — Slider assembly illustrating the maximum wear on striking edge
The mass of the pendulum arm, including the slider assembly, shall be (1,50 ± 0,03) kg. The centre of 6.2 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 slider rubber (76,2 ± 0.5) mm wide, (25,4 ± 1,0) mm long (in the direction of swing) and (6,35 ± 0,5) mm thick and an aluminium backing. The combined mass of slider assembly shall be (32 ± 5) g.
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6.4 The narrow slider (see Figure 3 ) shall consist of a slider rubber (31,75 ± 0,5) mm wide, (25,4 ± 1,0) mm long 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 slider rubber shall be vulcanized onto the backing.
6.6 The slider rubber shall be provided with a certificate from the supplier giving the hardness at a range of temperatures and the resilience to confirm compliance with Table 1 of this standard. 6.7 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. 6.8 The slider rubber shall be spring-loaded against the test surface. The nominal static force on the slider assembly as set by the equipment calibration procedure, defined in Annex A.2 shall be (22,2 ± 0.5) N in its median position. The change in the static force on the slider shall be not greater than 0,2 N per millimetre deflection of the slider. 6.9 The initial resilience measured by the “Lübke Rebound Test” in accordance with ISO 4662:1986 and hardness of the slider rubber, measured by the International Hardness Rubber Degrees (IRHD) in accordance with ISO 48, shall comply with Table 1 (CEN rubber). It shall have a certificate of conformity including the name of the manufacturer and date of manufacture. 6.9.1 A slider shall be discarded when the IRHD value measured using the portable hardness tester in accordance with ISO 7619 falls below the minimum tolerance given in Table 1 or not later than 1 year after manufacture. NOTE CEN rubber is normally used for surfaces subject to vehicular traffic. For surfaces subject to shoe or foot usage, as detailed in the relevant standards, a slider rubber known as 4S rubber may be required. It shall have an initial resilience and hardness as given Table 2.
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. Table 1 — Properties of the slider rubber (CEN rubber) Temperature °C
Property
Lübke Resilience (%) )
Hardness (IRHD) 2 NOTE 1
0
10
20
30
40
43 to 49
58 to 65
66 to 73
71 to 77
74 to 79
53 to 65
The rubber composition presented in Annex C has been found to be satisfactory
Table 2 — Properties of the slider rubber (4S rubber) Temperature °C
Property
Lübke Resilience (%) )
Hardness (IRHD) 2
5
23
40
19 to 23
21 to 26
26 to 30
94 to 98
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6.11 Before using a new slider rubber it shall be conditioned to achieve a minimum width of sliding edge of 1 mm as shown in Figure 3. NOTE This can be achieved by setting up the tester and carrying out sufficient swings wet or dry as described in 9. 2, to achieve the minimum width, using as a test specimen waterproof abrasive paper 400 grade, or lapping film 3 micron aluminium oxide, mounted on a glass plate as described in A.1.2.
6.12 The slider rubber shall be discarded when the width of the sliding edge, as shown in Figure 3, exceeds 3 mm or when it becomes excessively scored or burred. The slider assembly can be reversed to expose a new sliding edge, which will need to be conditioned. 6.13 The slider assembly shall be stored in a dry watertight bag in the dark at a temperature of (15 ± 10) °C. The cooler the storage temperature, the longer the properties in Tables 1 will be retained. Should the temperature of the rubber fall below 15 °C for a period in excess of one day during storage or during a series of tests, the slider assembly shall be raised to a temperature of (35 ± 5) °C for a period of (18 ± 6) hours before use on a subsequent occasion. The slider assembly shall be at ambient temperature when used.
7
Calibration
7.1 The apparatus shall be recalibrated at least annually by a competent calibration centre and a certificate provided. 7.2
Calibration of the tester is described in Annex A.2.
7.3
The calibration procedure shall include reference surfaces covering the working range of the tester.
7.4 In addition the validation procedure described in Annex A.1 shall be carried out prior to and following its use for testing.
8
Apparatus
Potable water for wetting the surface in a container and dispenser to apply (100 ± 20) ml of water onto 8.1 the test surface before each swing. 8.2
Radiation thermometer (pyrometer), or electronic thermometer with a surface probe, accurate to 1 °C.
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-metal hand brush for cleaning the surface.
8.5
Optional: A portable anemometer accurate to 2 m/s field use.
9 9.1
Test Measurements 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. The surface shall be free of ice. 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 6 %. 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.
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9.1.3 Measure the temperature of the test surface and the slider to the nearest whole number. The test cannot be carried out if the surface temperature is outside the range 1 °C to 40 °C. 9.1.4 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.
9.2
Measurements in the laboratory
9.2.1 Flat laboratory test specimens shall have minimum dimensions 20 mm wider than the slider and 15 mm longer than the sliding length. Curved specimens for the Polished Stone Value test shall have a test surface as described in EN 1097-8. 9.2.2 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. 9.2.3 The appropriate slider assembly with either a CEN rubber slider or 4S rubber slider shall be selected as required. 9.2.4 Specimens cut from a surface shall use a method of cutting or coring to ensure the surface to be tested remains undamaged. 9.2.5 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.
9.2.6 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. 9.2.7 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. NOTE On surfaces typical of those found on roads, about 100 ml of water is required to be applied to the surface immediately prior to each swing.
9.2.8 Laboratory tests shall be carried out with the specimens held for a minimum of 30 minutes 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 the width 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.
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NOTE 2 Surfaces which have ridges, edges of blocks or paving stones, or have a surface roughness in excess of 1.2 mm measured by the patch test (EN 13036-1 or an equivalent measured by MPD in accordance with ISO 13473-1) can arrest the movement of the pendulum and the test is inappropriate. 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 The number of samples necessary to obtain the PTV of an area will be dependent upon the variability of the surface. NOTE A minimum of three tests should be taken. These should be measured not more than 400 mm apart to obtain the mean value for a location.
11 Test procedure 11.1 The pendulum test equipment shall be transported in the box supplied with the equipment. 11.2 The appropriate slider assembly with either a CEN rubber slider or 4S rubber slider shall be selected as required. 11.3 Ensure that the slider rubber satisfies the requirements of Clauses 6.8 and 6.9 before commencing work. NOTE If the slider assembly is being used on a contaminated surface, the test result will be affected. The slider rubber should be reconditioned by carrying out three swings over the wetted conditioning surface as described in 6.8.
11.4 In the field, check the surface or slider rubber temperature at each test location. If used a pyrometer shall be orientated perpendicular to the direction of the surface. 11.5 Adjust the levelling screws so that the pendulum support column is vertical. Then 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 and pointer are released from the right-hand horizontal position the pointer comes to rest at zero position on the test scale. NOTE 1 The check required by Paragraph 11. 5 ensures that the tester is still functioning properly. This adjustment is necessary when the tester is used under di fferent temperature conditions. NOTE 2
It is advisable to carry out 10 free swings to verify the consistency of the zero reading.
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 b y passing traffic.
11.6 Adjust the height of the pendulum arm so that in traversing the surface the rubber slider is in contact with it over the whole width of the slider and over the required length. This is normally accomplished in a series of small steps, using the gauge/scale provided with the machine and shown in Figure 2, as follows: 11.6.1 Raise/lower the Pendulum head so that the slider is just clear of the surface. 11.6.2 Position the centre of the gauge approximately level with the rear edge of the slider backing plate. 11.6.3 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 level with the right outermost mark on the gauge. Either clamp or manually hold the head in that position. 11.6.4 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. 11.6.5 Allow the Pendulum foot to gently drop back so that the slider contacts the test surface.
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11.6.6 The rear edge of the slider should lie in between the two left hand gauge marks. If not, then raise or lower the Pendulum head so that the slider moves about 50 % of the distance towards the correct setting. 11.6.7 Reclamp the head, reposition the gauge so that the corner of the slider is level with the left hand outermost gauge mark and then move the Pendulum foot over to the right hand side and check if it lines up with the right hand gauge marks. If not, repeat the process, backwards and forwards until the Pendulum head is set at the correct height to give a 126 ± 1 mm contact length. NOTE Although the contact length ought ideally to be measured between the actual points of contact of the slider to the test surface, it has been found far more convenient to use the rear top corner of the slider backing plate as the reference point.
11.7 Wet the surfaces of the specimen and the rubber slider with (100 ± 20) ml water, being careful not to disturb the slider from its set position. 11.8 As quickly as possible thereafter, release the pendulum and pointer from the horizontal position using the holding button, 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 and pointer to the release position by raising the slider using the lifting handle. 11.9 Perform this operation five times, re-wetting the surface as above 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. 11.10 On completion of testing, check the equipment is still level and swing the pendulum as described in Clause 11.5 Note 2 to ensure there has been no disturbance during testing. If this is apparent, discard the results and repeat the test. 11.11 In the field, recheck the slide contact length and recheck the temperature of wetted surface or slider rubber on completion of the test. 11.12
Carry out the required number of tests as described in Clause 10.
12 Calculations 12.1 Calculate the PTV as the mean of five swings using the formula
∑
PTV =
(v1 + v2 + v3 + v4 + v5 ) 5
(1)
where v1 to v5
or
are individual values for each swing
PTV = v j
where v j
is the constant value achieved by three swings if the initial swings are too variable (see 11.8).
12.2 Report the PTV to the nearest whole number. 12.3 Correct the mean value for temperature using the nearest temperature from Table 3 below. 12.4 Report the corrected PTV ( PTV CORR) to the nearest whole number.
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12.5 The PTV is obtained on a flat surface/specimen with either a wide slider over 126 mm nominal swept length. The results for a narrow slider on a flat surface/specimen over a 76 mm nominal swept length shall be divided by a factor of 1,1 to obtain the PTV within 10 %. Table 3 — Correction of PTV when the test is carried out at other than 20 ºC using CEN slider rubber Measured Temperature °C
NOTE
Correction to measured value
36-40
+3
29-35
+2
23-28
+1
19-22
0
16-18
-1
12-15
-2
8-11
-3
5-7
-4
The temperature correction can be affected by the texture of the surface
No temperature correction is required for PTV when the test is carried out at other than 20 °C using 4S (Standard Pedestrian Hard Rubber) slider rubber.
13 Precision Repeated tests show standard deviation of 1,0 surface.
PTV ;
uncorrected for temperature on a fine-textured, plane
NOTE 1
Coarse textured or very smooth surfaces will reduce the precision of the test.
NOTE 2
The use of the temperature correction in Table 3 will reduce the precision of the test.
NOTE 3
The determination of the precision in accordance with CEN rules has not been carried out.
NOTE 4 In order that precision quoted above is obtained the test should be carried out by trained and competent operatives.
14 Test report 14.1 The field test report shall include the following information (see Annex D):
a) reference to this European Standard; 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);
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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) wet surface temperature of the tested area; i)
whether the slider assembly was wide or narrow;
j)
whether CEN slider rubber or 4S slider rubber was used;
k)
number of the slider rubber;
l)
mean PTV and mean PTV CORR at each test position, and for each area of surface (if required);
m) any pertinent remarks about the surface type. 14.2 The laboratory test report shall include the following information:
a) reference to this European Standard; 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 CEN slider rubber or 4S slider rubber was used; h) number of the slider rubber; i)
mean PTV of the specimen;
j)
any pertinent remarks about the test specimen.
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Annex A (normative) Validation and calibration of the Pendulum Friction Tester
A.1 Validation of the performance of the pendulum A.1.1 General To ensure consistency of readings, the operation of the pendulum tester shall be validated, prior A.1.1.1 to and after use using the method described below. The validation procedure comprises one set of readings in the wet condition on two standard A.1.1.2 surfaces, representing high and low PTV . The standard surfaces shall be float glass, free from contamination and scratches and a piece of A.1.1.3 abrasive paper mounted on float glass. The abrasive paper shall be used on one day only. The validation procedure shall be performed with the pendulum tester upon return from calibration A.1.1.4 and prior to use for any testing. The values obtained shall be used to monitor the performance of the operation of the pendulum tester until it is next calibrated. Float glass shall have a PTV in the range 5 to 10. The abrasive paper shall have a PTV in the A.1.1.5 range 50 to 70. Should the value obtained from any daily check vary by more than 4 units from the value obtained A.1.1.6 on return from calibration, the operation of the pendulum tester shall be investigated. Should the value obtained between start and finish checks on any one day by more than 2 units, A.1.1.7 the operation of the pendulum tester shall be investigated. NOTE correctly.
The procedure may also be used to ensure that the operative is using the procedures in this standard
A.1.2 Procedure The laboratory shall maintain a piece of float glass for validation testing and for no other purpose. A.1.2.1 The side tested shall be identified and used. The size shall be at least 120 mm by 100 mm by 10 mm thick as shown in Figure A1. The laboratory shall maintain a stock of abrasive paper, grade 3 micron, aluminium oxide A.1.2.2 abrasive mounted on a waterproof backing film. The abrasive paper shall be mounted on a piece of float glass used for validation testing and for no other purpose. The abrasive paper 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.
Both the float glass and abrasive surface shall be tested wet using the method described in A.1.2.3 Clause 11 except that instead of potable water as specified in 8.1, de-ionized or distilled water shall be used.
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Key
1 2 3 4 5
area of adhesion glass plate abrasive paper direction of swing swept area Figure A.1 — Fixing of sheet to plate
A.2
Calibration of the pendulum
NOTE
A.2.1 A.2.1.1
This procedure shall only be a carried by an approved calibration centre
Checking/setting the centre of gravity of the pendulum arm and slider assembly Mass of the arm
Remove the pendulum arm from the main frame of the apparatus and weigh it using the balance. Record this value. If the mass is not (1,50 ± 0,03) kg, consult the manufacturer. A.2.1.2
Longitudinal position of the centre of gravity
Place the tubular part of the arm across one of the horizontal knife edges such that the arm balances. Mark the position of the point of balance on the arm (see Figure A.2). NOTE The longitudinal centre line of the arm should be at right angles to the horizontal axis of the knife edge and the adapter nut located as far from the foot as possible.
side view
end view
Key
1 2 3 4 5 Figure A.2 — Pendulum arm, showing the location of the centre of gravity
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prEN 13036-4:2009 (E)
A.2.1.3
Lateral position of the centre of gravity
Place the tubular part of the arm on, and at right angles to, two horizontal knife edges (placed A.2.1.3.1 approximately 300 mm apart and parallel with each other such that the longitudinal centre of gravity of the arm as determined in A.2.1.2. lies between the knife edges. NOTE
The arm should be free to roll along the knife edges.
If there is a tendency for the foot part of the arm assembly to rotate, adjust the counterweight on A.2.1.3.2 the rear of the foot to obtain the correct balance. NOTE
If correctly balanced, the foot part of the arm assembly lies in a horizontal plane with no tendency to rotate.
A.2.1.3.3
Fully tighten the counterweight assembly.
A.2.1.4
Distance of centre of gravity to centre of rotation
Reassemble the arm onto the main frame and measure the distance from the point of balance A.2.1.4.1 as specified in A.2.2 to the centre of the main bearing. A.2.1.4.2 NOTE
A.2.2
Record this distance. If the measured distance is not (410 ± 5) mm, consult the manufacturer.
Checking/setting the effective spring tension
NOTE The method detailed here is suitable for pendulum testers manufactured to the original RRL design and which incorporate a special calibration threaded hole in the slider lift arm.
A.2.2.1
Calculating the correct spring tension force
A.2.2.1.1
Calculate the correct spring tension force using the following equation:
F = (24,5 × W × L)/(1
500
×
410) – 2,3
(A.1)
where F W L
A.2.2.2
is the correct spring tension force, in Newton (N); is the mass of the arm as determined in accordance with A.2.1.2, in grams (g); is the distance to the centre of gravity as determined in accordance with A.2.1.3, in millimetres (mm). Checking/setting the actual spring tension force
Remove the pendulum arm from the main frame of the apparatus and clamp it upside down (with A.2.2.2.1 the tubular arm vertical). Expose the tapped hole in the slider lift arm. NOTE
For some designs, unscrew the small plate to the side of the slider lift arm.
A.2.2.2.2
Screw a 6BA stud or bolt into the tapped hole in the slider lift arm.
A.2.2.2.3 0,1 mm.
Measure the vertical position of the stud, in relation to a convenient datum point, to the nearest
A.2.2.2.4
Apply a vertical force to the stud until the stud drops 4,5 mm.
A.2.2.2.5
Record the value of the force measured.
18
prEN 13036-4:2009 (E)
If the force applied is not within the range ( F ± 0,5) N, undo the clamp at the bearing end of the A.2.2.2.6 pendulum arm and rotate the top section relative to the tubular arm until the correct tension is achieved. Prior to re-tightening the clamp, ensure that the location hole points to the centre of the toe of the foot of the pendulum arm. Reassemble the arm onto the main frame and adjust the foot so that it is parallel to the frame and remains parallel during its swing. A.2.2.2.7 A.2.3
Fully tighten the clamp screws.
Checking/setting the levelness of the frame
A.2.3.1
Levelling the frame
Set the pendulum frame up with the arm now attached to the main frame. Adjust the feet such A.2.3.1.1 that the pendulum tester is level according to the built in level. Using a spirit level, accurate to within 4 minutes of arc (0,06°) or 1 in 1 000, or by equivalent A.2.3.1.2 means, check the verticality of the main upright tube in two directions at right angles. Record the extent of any non-verticality in excess of 0,5° (1 in 120) and either adjust the built in A.2.3.1.3 level or consult the manufacturer. Check that when the pendulum arm is engaged in the release catch that its longitudinal axis lies A.2.3.1.4 in a horizontal line. Record the extent of any deviation from the horizontal in excess of 0,5° (1 in 120) and either A.2.3.1.5 adjust the catch block or consult the manufacturer. A.2.3.1.6
Measure the vertical distance between the arm centre of rotation and the zero mark on the scale.
Record the extent of any deviation in excess of (10 ± 1) mm and either adjust the scale or consult A.2.3.1.7 the manufacturer. A.2.4
Adjusting the pointer
Allow the pendulum arm to hang freely. Place the pointer alongside it in its “following” position. A.2.4.1 Turn the follower adjustment screw such that the follower main longitudinal axis is precisely in line with the axis of the pendulum arm. The longitudinal axes of the main upright tube on the frame, the pendulum arm and the pointer shall all be in line and vertical. A.2.5
Final calibration
Repeat the procedure specified in A.1.2. Check that the A.2.5.1 previously found on the reference surfaces
PTV is
within
± 5
units of the value
If the PTV is outside these limits, investigate and correct the cause of the deviation and then A.2.5.2 repeat the procedures specified in Clauses A.2 as necessary. A.2.6 A.2.6.1
Calibration report and marking Calibration report
The pendulum tester calibration report shall include the following: a)
number and date of this European Standard;
b)
name of the calibration laboratory and the laboratory certifying body;
c)
serial number of the pendulum tester;
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prEN 13036-4:2009 (E)
d)
organization for whom the calibration has been carried out;
e)
date of calibration;
A.2.6.2
Marking
A label shall be affixed to the pendulum tester stating: a)
number and date of this European Standard,
b)
name of the calibration laboratory;
c)
serial number of the pendulum tester;
d)
calibration certificate number;
e)
date of calibration;
f)
date when the next calibration is required to be carried out, which shall be no more than 12 months after the date of calibration (e).
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prEN 13036-4:2009 (E)
Annex B (normative) Details of Scales
Table B.1 C scale Graduation
F scale Drop mm
mm below horizontal
Graduation
(where present) Drop mm
mm below horizontal
0
0,00
10,16
0
0,00
10,16
5
7,13
17,29
0,1
8,64
18,80
10
14,26
24,42
0,2
17,02
27,18
15
21,39
31,55
0,3
25,65
35,81
20
28,52
38,68
0,4
34,45
44,60
25
35,65
45,81
0,5
42,67
52,83
30
42,78
52,94
0,6
51,80
62,30
35
49,91
60,07
0,7
59,94
70,10
40
57,04
67,20
0,8
68,58
78,74
45
64,17
74,33
0,9
76,96
87,12
50
71,30
81,46
1,0
85,60
95,76
55
78,43
88,59
60
85,56
95,72
65
92,69
102,85
70
99,82
109,98
75
106,95
117,11
80
114,08
124,24
85
121,21
131,37
90
128,34
138,50
95
135,47
145,63
100
142,60
152,76
105
149,73
159,89
110
156,86
167,02
115
163,99
174,15
120
171,12
181,28
125
178,25
188,41
130
185,38
195,54
135
192,51
202,67
140
199,64
209,80
145
206,77
216,93
150
213,90
224,06
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prEN 13036-4:2009 (E)
Key
1 2 3
drop scale radius 305 mm horizontal line through axis of rotation Figure B.1
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prEN 13036-4:2009 (E)
Annex C (informative) Typical Composition of the CEN Slider Rubber
Elastomer:
Part by mass
a)
natural (unprocessed) rubber (SMR-L)
100,00
b)
stearic acid
c)
ageing preservative: (Vulkanox 4010 NA)
d)
zinc oxide
e)
carbon black according to ASTM N 990 (Sevacarb MT)
f)
accelerator: Benzothiazly-2-cyclohexysulphonamide (Vulkacit CI)
6,0
g)
aromatic oil (Nigrex 981)
4,0
h)
sulphur
2,5
2,0 N-isopropyl-N’-phenyl-p-phenylenediamene
(IPPD)
1,0 3,0 75,0
Backing plate: Dural plate. Bonding of the metal with the elastomer takes place during the vulcanization (145 °C, 30 minutes) using a primer and the adhesive Megum 3270
23
