CEN/TS 15901-11:2011

SLOVENSKI STANDARD
01-junij-2011
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Road and airfield surface characteristics - Part 11: Procedure for determining the skid
resistance of a pavement surface using a device with longitudinal block measurement
(LFCSR): the SRM
Oberflächeneigenschaften von Straßen und Flugplätzen - Teil 11: Verfahren zur
Bestimmung der Griffigkeit von Fahrbahndecken durch Messung des Gleitbeiwertes am
blockierten Schlepprad: das SRM-Messgerät
Caractéristiques de surface des revêtements de chaussée des routes et des aérodromes
- Partie 11: Mode opératoire de détermination de l'adhérence de la surface d'un
revêtement de chaussée à l'aide d'un dispositif de mesure longitudinale, roue bloquée
(CFLSR): le SRM
Ta slovenski standard je istoveten z: CEN/TS 15901-11:2011
ICS:
17.040.20 Lastnosti površin Properties of surfaces
93.080.10 Gradnja cest Road construction
93.120 *UDGQMDOHWDOLãþ Construction of airports
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 15901-11
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2011
ICS 93.080.20; 93.120
English Version
Road and airfield surface characteristics - Part 11: Procedure for
determining the skid resistance of a pavement surface using a
device with longitudinal block measurement (LFCSR): the SRM
Caractéristiques de surface des revêtements de chaussée Oberflächeneigenschaften von Straßen und Flugplätzen -
des routes et des aérodromes - Partie 11: Mode opératoire Teil 11: Verfahren zur Bestimmung der Griffigkeit von
de détermination de l'adhérence de la surface d'un Fahrbahndecken durch Messung des Gleitbeiwertes
revêtement de chaussée à l'aide d'un dispositif de mesure (LFCSR) am blockierten Schlepprad: das SRM-Messgerät
longitudinale, roue bloquée (CFLSR): le SRM
This Technical Specification (CEN/TS) was approved by CEN on 14 September 2010 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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
COMITÉ EUROPÉEN DE NORMALISATION

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 Ref. No. CEN/TS 15901-11:2011: E
worldwide for CEN national Members.

Contents
Page
Foreword .3
1 Scope .4
2 Recommended uses .4
3 Terms and definitions .4
4 Safety .6
5 Principle .6
5.1 Principle of measurements .6
5.2 Operating principle .7
6 Key characteristics .7
6.1 General .7
6.2 Test equipment .7
6.3 Test wheel assembly .8
6.4 Test tyre .8
6.5 Water supply and flow control .8
6.6 Parameters recorded .8
7 Test procedure .9
7.1 Standard testing conditions .9
7.2 Prior to testing .9
7.3 Testing .9
8 Data recording . 10
9 Calibration . 10
10 Precision . 10
11 Test report . 11
Bibliography . 12

Foreword
This document (CEN/TS 15901-11:2011) has been prepared by Technical Committee CEN/TC 227 “Road
materials”, the secretariat of which is held by DIN.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: 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 Technical Specification describes a method for determining the skid resistance of paved surface by
measurement of the longitudinal friction coefficient µ
SRM
The method provides a measure of the wet skid resistance properties of a bound surface by measurement of
the longitudinal friction coefficient using a locked wheel with a slip ratio of 0 % (locked wheel: standard), or a
slip ratio of (15 ± 1) % or ABS and a controlled speed. The test tyre is dragged over a pre-wetted pavement
under controlled load and constant speed conditions while the test tyre is parallel to the direction of motion
and to the pavement.
This document covers the operation of the Stuttgarter Reibungsmesser (SRM) of the IVT ETH Zürich.
2 Recommended uses
This method provides a means for the evaluation of the skid resistance of a road surface. It is suitable for use
in the following situations:
 For measurement of road in service, either network monitoring for pavement management, or
measurements on project-level;
 approval of new or renewed pavements;
 research measurements;
 special measurements with separately defined measuring method in winter conditions (ice, snow, frost).
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
friction
resistance to relative motion between two bodies in contact
NOTE The frictional force is the force which acts tangentially in the contact area.
3.2
skid resistance
characterisation of the friction of a road surface when measured in accordance with a standardised method
3.3
wet road skid resistance
property of a trafficked surface that limits relative movement between the surface and the part of a vehicle tyre
in contact with the surface, when lubricated with a film of water
NOTE Factors that contribute to skid resistance include the tyre pressure, contact area, tread pattern, and rubber
composition; the alignment, texture, surface contamination, and characteristics of the road surface; the vehicle speed; and
the weather conditions.
The skid resistance of a road surface in Europe varies seasonally. Generally, wet skid resistance is higher in winter as a
result of the effects of wet detritus and the effects of frost and wear by tyres on microtexture and macrotexture. Wet skid
resistance is lower in summer as a result of dry polishing by tyres in the presence of fine detritus.
The change in skid resistance of a surface in service is affected by the volume of traffic and the composition of the traffic,
i.e. cars, buses, commercial vehicles of different sizes, as the tyres of these vehicles polish and/or wear away the
surfacing material in different ways. The geometry of the road will affect the change in skid resistance. Generally, tyres
polish less on straight roads than on bends.
Where the surface contains aggregate with a coating of binder, e.g. bitumen, resin of Portland cement, the skid resistance
will change as the coating is worn away by tyres.
3.4
longitudinal friction coefficient
LFC
ratio between horizontal force (drag) and vertical load (load) for a braked wheel in controlled conditions
NOTE 1 This is normally a decimal number quoted to two significant figures.
NOTE 2 LFC varies depending on the slip ratio of the device and the operational speed.
3.5
Longitudinal friction coefficient
SRM µ
SRM
ratio under controlled slipping conditions between the horizontal force (that can be activated between the test
wheel and the wet surface) and the vertical wheel load of the Skiddometer
3.6
calibration
periodic adjustment of the offset, the gain and the linearity of the output of a measurement method so that all
the calibrated devices of a particular type deliver the same value within a known and accepted range of
uncertainty, when measuring under identical conditions within given boundaries or parameters
NOTE The method of calibration of the reference device is given in Clause 6.
3.7
SRM
acronym SRM applies to a device developed by Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren
Stuttgart (FKFS) to perform routine measurements of friction for long road-sections or punctual measurements
at different speeds to characterise a particular section
3.8
operating speed
speed at which the device traverses the surface
3.9
slip speed
relative speed between the test tyre and the travelled surface in the contact area
3.10
slip ratio
quotient of the slip speed divided by the operating speed
3.11
wheel path
parts of the pavement surface where the majority of vehicle wheel passes are concentrated
NOTE The wheel path is not a fixed location on a pavement surface. On a worn pavement, the wheel path is usually
easily identified visually. On a newly laid surface, the position of the wheel path has to be estimated by experienced
operators.
For special circumstances such as acceptance tests, a particular path may be defined, for example, (700 ± 150) mm from
the edge of the running lane of a road.
3.12
theoretical water film thickness
theoretical thickness of a water film deposited on the surface in front of the measuring tyre, assuming the
surface has zero texture depth
3.13
repeatability
maximum difference expected between two measurements made by the same machine, with the same tyre,
operated by the same crew on the same section of road in a short space of time, with a probability of 95 %
3.14
reproducibility
maximum difference expected between two measurements made by different machines, with different tyres,
operated by different crews on the same section of road in a short space of time, with a probability of 95 %
4 Safety
Safety measures shall be in place to maintain safe working practice in accordance with current regulations,
and to ensure the safety of other road users, including measures to control traffic as necessary.
NOTE The wetting of surfaces can have an effect on other users of the site and every effort should be made to
ensure that they do not have to make any sudden changes in speed or direction.
When measuring skid resis
...