SIST-TS CEN/TS 15901-15:2014

Road and airfield surface characteristics - Part 15: Procedure for determining the skid resistance of a pavement surface using a device with longitudinal controlled slip (LFCI): The IMAG

This Technical Specification describes a method only used on airports for determining the skid resistance of pavements by measurement of the longitudinal friction coefficient LFCI.
The method provides a measure of the wet skid resistance properties of a bound surface by measurement of the longitudinal friction coefficient using a trailer with a standard slip ratio of 15 %. The slip ratio can be chosen between 0 % and 100 % for research application.
The test tyre is dragged over a pre wetted pavement under vertical force and constant speed conditions while the test tyre is parallel to the direction of motion.
This Technical Specification covers the operation of the IMAG device.
The skid resistance of a pavement is determined by friction measurements at different speeds. Tests can be performed between 40 km/h and 120 km/h but standard test speeds are 40 km/h, 65 km/h and 95 km/h. Low speed measurements asses the microtexture while high speed measurements asses the macrotexture. The skid resistance is reported as friction measurements at these speeds and by comparison with the minimum friction level.

Oberflächeneigenschaften von Straßen und Flugplätzen - Teil 15: Verfahren zur Bestimmung der Griffigkeit von Fahrbahndecken durch Verwendung eines Geräts mit geregeltem Schlupf in Längsrichtung (LFCE): Das IMAG-Gerät

Diese Technische Spezifikation beschreibt ein Verfahren für die Bestimmung der Griffigkeit von Fahrbahndecken durch Messung des Reibungskoeffizienten in Längsrichtung LFCE, das nur an Flugplätzen angewendet wird.
Das Verfahren liefert ein Maß für die Nassgriffigkeitseigenschaften einer gebundenen Oberfläche durch Messung des Reibungskoeffizienten in Längsrichtung mit Hilfe eines Anhängers mit einem Schlupfverhältnis von 15 % (Normwert). Für Forschungsmessungen kann das Schlupfverhältnis zwischen 0 % und 100 % gewählt werden.
Der Messreifen wird mit vertikaler Kraft und geregelter Geschwindigkeit über eine zuvor angenässte Fahrbahndecke gezogen, wobei er parallel zur Bewegungsrichtung läuft.
Diese Technische Spezifikation behandelt den Betrieb des IMAG-Geräts.
Die Griffigkeit einer Fahrbahn wird durch Reibungsmessungen bei verschiedenen Geschwindigkeiten festgelegt. Prüfungen können bei Geschwindigkeiten zwischen 40 km/h und 120 km/h durchgeführt werden, die Normwerte für Messgeschwindigkeiten sind jedoch 40 km/h, 65 km/h und 95 km/h. Messungen bei niedriger Geschwindigkeit beurteilen die Mikrotextur, wohingegen Messungen bei hoher Geschwindigkeit die Makrotextur der Fahrbahn beurteilen. Die Griffigkeit ist als Reibungsmessungen bei diesen Geschwindigkeiten und durch den Vergleich mit dem minimalen Reibungsgrad angegeben.

Caractéristiques de surface des routes et aéroports - Partie 15: Mode opératoire de détermination de l'adhérence d'un revêtement de chaussée à l'aide d'un dispositif à glissement longitudinal contrôlé (CFLI): IMAG

La présente Spécification technique décrit une méthode utilisée uniquement pour les aéroports, permettant de déterminer l’adhérence des revêtements de chaussées par mesure du coefficient de frottement longitudinal CFLI.
La méthode permet de mesurer les propriétés d'adhérence d'une couche de roulement mouillée, en déterminant le coefficient de frottement longitudinal à l'aide d'une remorque ayant un taux de glissement normalisé de 15 %. Le taux de glissement peut être choisi entre 0 % et 100 % à des fins de recherche.
Le pneumatique d’essai est tracté sur une chaussée préalablement mouillée, dans des conditions d'effort vertical et de vitesse constante, le pneumatique d'essai étant parallèle à la direction du mouvement.
La présente Spécification technique porte sur le fonctionnement de l’appareil IMAG.
L'adhérence d'une chaussée est déterminée par des mesures du frottement à différentes vitesses. Les essais peuvent être effectués à une vitesse comprise entre 40 km/h et 120 km/h, mais les vitesses d'essai normalisées sont de 40 km/h, 65 km/h et 95 km/h. Les mesures à faible vitesse évaluent la microtexture alors que les mesures à vitesse élevée évaluent la macrotexture. L'adhérence est consignée dans le rapport sous forme de mesures du frottement à ces vitesses et par comparaison au niveau de frottement minimal.

Značilnosti cestnih in letaliških površin - 15. del: Postopek določanja torne sposobnosti vozne površine z mehanizmom za kontroliran zdrs v vzdolžni smeri (LFCI): IMAG

Ta tehnična specifikacija opisuje metodo, ki se uporablja le na letališčih za določanje torne sposobnosti površin z meritvijo količnika trenja LFCI.
Metoda določa merilo lastnosti tornih sposobnosti mokre omejene površine z meritvijo količnika trenja z uporabo priklopnika s standardno stopnjo zdrsa pri 15 %. Izbrati je mogoče stopnjo zdrsa med 0 % do 100 % za raziskovalne meritve.
S preskusno pnevmatiko se zavira na predhodno namočeni površini pod nadzorovanimi pogoji navpične sile in hitrosti, medtem ko je preskusna pnevmatika vzporedna s smerjo gibanja.
Ta tehnična specifikacija obravnava delovanje mehanizma IMAG.
Torna sposobnost površine je določena z meritvami trenja pri različnih hitrostih. Preskuse je mogoče izvajati pri hitrostih med 40 km/h in 120 km/h, vendar so standardne preskusne hitrosti 40 km/h, 65 km/h in 95 km/h. Z merjenji pri nizkih hitrostih se ocenjuje mikrotekstura, z merjenji pri visokih hitrostih pa makrotekstura. Torna sposobnost je predstavljena kot meritve trenja pri teh hitrostih in s primerjavo z najmanjšo ravnjo trenja.

General Information

• Status: Published
• Public Enquiry End Date: 29-Jan-2014
• Publication Date: 23-Nov-2014
• ICS: 17.040.20 - Properties of surfaces
• ICS: 93.080.10 - Road construction
• ICS: 93.120 - Construction of airports
• Technical Committee: CES - Roads
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 06-Nov-2014
• Due Date: 11-Jan-2015
• Completion Date: 24-Nov-2014
• Ref Project: CEN/TS 15901-15:2014 - Road and airfield surface characteristics - Part 15: Procedure for determining the skid resistance of a pavement surface using a device with longitudinal controlled slip (LFCI): The IMAG

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS CEN/TS 15901-15:2014
01-december-2014
=QDþLOQRVWLFHVWQLKLQOHWDOLãNLKSRYUãLQGHO3RVWRSHNGRORþDQMDWRUQH
VSRVREQRVWLYR]QHSRYUãLQH]PHKDQL]PRP]DNRQWUROLUDQ]GUVYY]GROåQLVPHUL
/)&,,0$*
Road and airfield surface characteristics - Part 15: Procedure for determining the skid
resistance of a pavement surface using a device with longitudinal controlled slip (LFCI):
The IMAG
Oberflächeneigenschaften von Straßen und Flugplätzen - Teil 15: Verfahren zur
Bestimmung der Griffigkeit von Fahrbahndecken durch Verwendung eines Geräts mit
geregeltem Schlupf in Längsrichtung (LFCE): Das IMAG-Gerät
Caractéristiques de surface des routes et aéroports - Partie 15: Mode opératoire de
détermination de l'adhérence d'un revêtement de chaussée à l'aide d'un dispositif à
glissement longitudinal contrôlé (CFLI): IMAG
Ta slovenski standard je istoveten z: CEN/TS 15901-15:2014
ICS:
17.040.20 Lastnosti površin Properties of surfaces
93.080.10 Gradnja cest Road construction
93.120 *UDGQMDOHWDOLãþ Construction of airports
SIST-TS CEN/TS 15901-15:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN/TS 15901-15:2014

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SIST-TS CEN/TS 15901-15:2014

TECHNICAL SPECIFICATION
CEN/TS 15901-15

SPÉCIFICATION TECHNIQUE

TECHNISCHE SPEZIFIKATION
October 2014
ICS 93.080.20; 93.120
English Version
Road and airfield surface characteristics - Part 15: Procedure for
determining the skid resistance of a pavement surface using a
device with longitudinal controlled slip (LFCI): The IMAG
Caractéristiques de surface des routes et aéroports - Partie Oberflächeneigenschaften von Straßen und Flugplätzen -
15: Mode opératoire de détermination de l'adhérence d'un Teil 15: Verfahren zur Bestimmung der Griffigkeit von
revêtement de chaussée à l'aide d'un dispositif à glissement Fahrbahndecken durch Verwendung eines Geräts mit
longitudinal contrôlé (CFLI): IMAG geregeltem Schlupf in Längsrichtung (LFCE): Das IMAG-
Gerät
This Technical Specification (CEN/TS) was approved by CEN on 1 March 2014 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15901-15:2014 E
worldwide for CEN national Members.

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
Contents Page
Foreword .3
1 Scope .5
2 Normative references .5
3 Recommended uses .5
4 Terms and definitions .6
5 Safety .9
6 Essential characteristics .9
6.1 Principle of measurements .9
6.2 Description of IMAG .9
7 Key characteristics . 11
7.1 General . 11
7.2 Test speed . 11
7.3 Braking system . 11
7.4 Static wheel load . 11
7.5 Dynamic wheel load . 11
7.6 Test wheel arrangement . 11
7.7 Test tyre . 11
7.8 Tyre and rim . 12
7.9 Force-measuring transducer . 12
7.10 Pavement wetting system, water film thickness . 12
7.11 Minimum sampling interval . 12
7.12 General requirements for measuring system . 12
8 Test Procedure . 12
8.1 Standard test conditions . 12
8.2 Prior to testing . 13
8.3 Testing . 13
9 Data recording . 14
10 Calibration . 14
10.1 General . 14
10.2 Calibration of the static vertical test wheel force . 14
10.3 Calibration of the static braking force . 14
10.4 Dynamic calibration of the travelled distance sensor . 14
10.5 Calibration of the water delivery system . 14
10.6 Dynamic comparison of friction devices . 15
11 Precision . 15
12 Test report . 15
Bibliography . 17

2

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
Foreword
This document (CEN/TS 15901-15:2014) 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 other than those identified above. CEN [and/or] CENELEC shall not be held responsible for identifying
any or all such patent rights.
CEN/TS 15901, Road and airfield surface characteristics, is composed with the following parts:
— Part 1: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal fixed slip ratio (LFCS): RoadSTAR;
— Part 2: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal controlled slip (LFCRNL): ROAR (Road Analyser and Recorder of Norsemeter);
— Part 3: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal controlled slip (LFCA): The ADHERA;
— Part 4: Procedure for determining the skid resistance of pavements using a device with longitudinal
controlled slip (LFCT): Tatra Runway Tester (TRT);
— Part 5: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal controlled slip (LFCRDK): ROAR (Road Analyser and Recorder of Norsemeter);
— Part 6: Procedure for determining the skid resistance of a pavement surface by measurement of the
sideway force coefficient (SFCS): SCRIM®;
— Part 7: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal fixed slip ratio (LFCG): the GripTester®;
— Part 8: Procedure for determining the skid resistance of a pavement surface by measurement of the
sideway-force coefficient (SFCD): SKM;
— Part 9: Procedure for determining the skid resistance of a pavement surface by measurement of the
longitudinal friction coefficient (LFCD): DWWNL skid resistance trailer;
— Part 10: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal block measurement (LFCSK): the Skiddometer BV-8;
— Part 11: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal block measurement (LFCSR): the SRM;
— Part 12: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal controlled slip: the BV 11 and Saab friction tester (SFT);
— Part 13: Procedure for determining the skid resistance of a pavement surface by measurement of a
sideway force coefficient (SFCO): the Odoliograph;
— Part 15: Procedure for determining the skid resistance of a pavement surface using a device with
longitudinal controlled slip (LFCI): The IMAG [the present document].
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,
3

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
4

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
1 Scope
This Technical Specification describes a method only used on airports for determining the skid resistance of
pavements by measurement of the longitudinal friction coefficient LFCI.
The method provides a measure of the wet skid resistance properties of a bound surface by measurement of
the longitudinal friction coefficient using a trailer with a standard slip ratio of 15 %. The slip ratio can be
chosen between 0 % and 100 % for research application.
The test tyre is dragged over a pre-wetted pavement under vertical force and constant speed conditions while
the test tyre is parallel to the direction of motion.
This Technical Specification covers the operation of the IMAG device.
The skid resistance of a pavement is determined by friction measurements at different speeds. Tests can be
performed between 40 km/h and 120 km/h but standard test speeds are 40 km/h, 65 km/h and 95 km/h. Low
speed measurements asses the microtexture while high speed measurements asses the macrotexture. The
skid resistance is reported as friction measurements at these speeds and by comparison with the minimum
friction level.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method
ASTM E670-09, Standard Test Method for Side Force Friction on Paved Surfaces Using the Mu-Meter
ASTM E2100-04, Standard Practice for Calculating the International Runway Friction Index
PIARC Technical Document. Specification for a standard test tyre for friction coefficient measurement of a
pavement surface: Smooth test tyre (2004-03)
3 Recommended uses
The IMAG is used in the following fields of application:
— monitoring of airport pavements (Pavement Management) according to ICAO Annex 14 Attachment A 7,
— approval of new surfacing according to ICAO Annex 14 Attachment A 7,
— investigation of surface skid resistance,
— measurements on project-level compliance,
— comparative measurements among different devices,
— measurements on contaminated (ice or snow covered) airport pavements (not covered by this Technical
Specification) according to ICAO Annex 14 Attachment A 6,
5

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
— research measurements.
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
contact area
overall area of the road surface instantaneously in contact with a tyre
Note 1 to entry: This term describes the overall area generally covered by the tyre. Due to the effects of surface
texture or any tyre tread pattern, not all of the tyre or road surface in the contact area may be in contact at any instant.
4.2
friction
resistance to relative motion between two bodies in contact, the frictional force being the force which acts
tangentially in the contact area
4.3
vertical force (load)
force applied by the wheel assembly on the contact area
Note 1 to entry: Some devices use an assumed load based on the static load.
4.4
horizontal force (drag)
horizontal force acting tangentially on the test wheel in line with the direction of travel
4.5
slip ratio
slip speed divided by the operating speed
4.6
longitudinal friction coefficient
LFC
ratio between horizontal force (drag) and vertical force (load) for a braked wheel in controlled conditions,
which is normally a decimal number quoted to two significant figures
Note 1 to entry: LFC varies depending on the slip ratio of the device and the operational speed.
4.7
skid resistance
characterisation of the friction of a road surface when measured in accordance with a standardized method
4.8
wet 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 1 to entry: Factors that contribute to skid resistance include the tyre pressure, contact area, tread pattern, and
rubber composition; the alignment, texture, surface pollution, and characteristics of the road surface; the vehicle speed;
and the weather conditions.
The change in skid resistance of a surface in service is affected by the volume of traffic and the composition of the traffic,
as the tyres of these vehicles polish and/or wear away the surfacing material in different ways. Rubber debris especially
affects wet skid resistance.
6

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SIST-TS CEN/TS 15901-15:2014
CEN/TS 15901-15:2014 (E)
Where the surface contains aggregate with a coating of binder, e.g. bitumen, resin or Portland cement, the skid resistance
will change as the coating is worn away by tyres.
4.9
fixed slip
condition in which a braking system forces the test wheel to roll at a fixed reduction of its operating speed
4.10
fixed slip friction
friction between a test tyre and a airfield surface when the wheel is controlled to move at a fixed proportion of
its natural speed
4.11
longitudinal friction coefficient IMAG
LFCI
ratio between the horizontal force in the direction of the motion that can be activated between the test wheel
and the wet pavement and the vertical wheel force accomplished under controlled slipping conditions
Note 1 to entry: The controlled slipping condition of the test wheel is achieved by a hydraulic pump and a hydraulic
servo-valve enslaved by the sensors of the IMAG.
4.12
sampling length or sampling interval
distance over which responses of the sensors are sampled to determine a single measurement of the
recorded variables
Note 1 to entry: The sampling length depends upon the detailed operation of device and its recording system; a
number of samples may be combined to determine a measurement for a subsection.
Note 2 to entry: This should not be confused with horizontal resolution which is the shortest distance over which a
change in the measured parameter can be detected.
4.13
microtexture
deviation of a pavement from a true planar pavement with characteristic dimensions along the pavement of
less than 0,5 mm, corresponding to texture wavelengths with one-third-octave bands and up to 0,5 mm centre
wavelengths
Note 1 to entry: Peak to peak amplitudes normally vary in the range 0,001 mm to 0,5 mm.
Note 2 to entry: Microtexture is a primary component in skid resistance at low speeds. Those devices that utilize a
relati
...

SLOVENSKI STANDARD
kSIST-TS FprCEN/TS 15901-15:2014
01-januar-2014
=QDþLOQRVWLFHVWQLKLQOHWDOLãNLKSRYUãLQGHO3RVWRSHNGRORþDQMDWRUQH
VSRVREQRVWLYR]QHSRYUãLQH]PHKDQL]PRP]DNRQWUROLUDQ]GUVYY]GROåQLVPHUL
/)&,,0$*
Road and airfield surface characteristics - Part 15: Procedure for determining the skid
resistance of a pavement surface using a device with longitudinal controlled slip (LFCI):
The IMAG
Oberflächeneigenschaften von Straßen und Flugplätzen - Teil 15: Verfahren zur
Bestimmung der Griffigkeit von Fahrbahndecken durch Verwendung eines Geräts mit
geregeltem Schlupf in Längsrichtung (LFCE): Das IMAG-Gerät
Caractéristiques de surface des routes et aéroports - Partie 15: Mode opératoire de
détermination de l'adhérence d'un revêtement de chaussée à l'aide d'un dispositif à
glissement longitudinal contrôlé (CFLI): IMAG
Ta slovenski standard je istoveten z: FprCEN/TS 15901-15
ICS:
17.040.20 Lastnosti površin Properties of surfaces
93.080.10 Gradnja cest Road construction
93.120 *UDGQMDOHWDOLãþ Construction of airports
kSIST-TS FprCEN/TS 15901-15:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST-TS FprCEN/TS 15901-15:2014

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kSIST-TS FprCEN/TS 15901-15:2014

TECHNICAL SPECIFICATION
FINAL DRAFT
FprCEN/TS 15901-15
SPÉCIFICATION TECHNIQUE

TECHNISCHE SPEZIFIKATION

October 2013
ICS 93.080.20; 93.120
English Version
Road and airfield surface characteristics - Part 15: Procedure for
determining the skid resistance of a pavement surface using a
device with longitudinal controlled slip (LFCI): The IMAG
Caractéristiques de surface des routes et aéroports - Partie Oberflächeneigenschaften von Straßen und Flugplätzen -
15: Mode opératoire de détermination de l'adhérence d'un Teil 15: Verfahren zur Bestimmung der Griffigkeit von
revêtement de chaussée à l'aide d'un dispositif à glissement Fahrbahndecken durch Verwendung eines Geräts mit
longitudinal contrôlé (CFLI): IMAG geregeltem Schlupf in Längsrichtung (LFCE): Das IMAG-
Gerät


This draft Technical Specification is submitted to CEN members for formal vote. It has been drawn up by the Technical Committee CEN/TC
227.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey 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 Technical Specification. It is distributed for review and comments. It is subject to change without notice
and shall not be referred to as a Technical Specification.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TS 15901-15:2013 E
worldwide for CEN national Members.

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kSIST-TS FprCEN/TS 15901-15:2014
FprCEN/TS 15901-15:2013 (E)
Contents
Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Recommended uses .4
4 Terms and definitions .5
5 Safety .8
6 Essential characteristics .8
6.1 Principle of measurements .8
6.2 Description of IMAG .8
7 Key characteristics .9
7.1 General .9
7.2 Test speed .9
7.3 Braking system .9
7.4 Static wheel load . 10
7.5 Dynamic wheel load . 10
7.6 Test wheel arrangement . 10
7.7 Test tyre . 10
7.8 Tyre and rim . 10
7.9 Force-measuring transducer . 10
7.10 Pavement wetting system, water film thickness . 10
7.11 Minimum sampling interval . 11
7.12 General requirements for measuring system . 11
8 Test Procedure . 11
8.1 Standard test conditions . 11
8.2 Prior to testing . 11
8.3 Testing . 12
9 Data recording . 12
10 Calibration . 12
10.1 General . 12
10.2 Calibration of the static vertical test wheel force . 13
10.3 Calibration of the static braking force . 13
10.4 Dynamic calibration of the travelled distance sensor . 13
10.5 Calibration of the water delivery system . 13
10.6 Dynamic comparison of friction devices . 13
11 Precision . 13
12 Test report . 14
Bibliography . 15


2

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kSIST-TS FprCEN/TS 15901-15:2014
FprCEN/TS 15901-15:2013 (E)
Foreword
This document (FprCEN/TS 15901-15:2013) 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 Formal Vote.
3

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kSIST-TS FprCEN/TS 15901-15:2014
FprCEN/TS 15901-15:2013 (E)
1 Scope
This Technical Specification describes a method only used on airports for determining the skid resistance of
pavements by measurement of the longitudinal friction coefficient LFCI.
The method provides a measure of the wet skid resistance properties of a bound surface by measurement of
the longitudinal friction coefficient using a trailer with a standard slip ratio of 15 %. The slip ratio can be
chosen between 0 % and 100 % for research application.
The test tyre is dragged over a pre-wetted pavement under vertical force and constant speed conditions while
the test tyre is parallel to the direction of motion.
This Technical Specification covers the operation of the IMAG device.
The skid resistance of a pavement is determined by friction measurements at different speeds. Tests can be
performed between 40 km/h and 120 km/h but standard test speeds are 40 km/h, 65 km/h and 95 km/h. Low
speed measurements asses the microtexture while high speed measurements asses the macrotexture. The
skid resistance is reported as friction measurements at these speeds and by comparison with the minimum
friction level.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
PIARC Technical Document. Specification for a standard test tyre for friction coefficient measurement of a
pavement surface: Smooth test tyre (2004-03))
ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic
method for the determination of repeatability and reproducibility of a standard measurement method
3 Recommended uses
The IMAG is used in the following fields of application:
 monitoring of airport pavements (Pavement Management) according to ICAO Annex 14 Attachment A 7,
 approval of new surfacing according to ICAO Annex 14 Attachment A 7,
 investigation of surface skid resistance,
 measurements on project-level compliance,
 comparative measurements among different devices,
 measurements on contaminated (ice or snow covered) airport pavements (not covered by this Technical
Specification) according to ICAO Annex 14 Attachment A 6,
 research measurements.
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4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
contact area
overall area of the road surface instantaneously in contact with a tyre
Note 1 to entry: This term describes the overall area generally covered by the tyre. Due to the effects of surface
texture or any tyre tread pattern, not all of the tyre or road surface in the contact area may be in contact at any instant.
4.2
friction
resistance to relative motion between two bodies in contact, the frictional force being the force which acts
tangentially in the contact area
4.3
vertical force (load)
force applied by the wheel assembly on the contact area
Note 1 to entry: Some devices use an assumed load based on the static load.
4.4
horizontal force (drag)
horizontal force acting tangentially on the test wheel in line with the direction of travel
4.5
slip ratio
slip speed divided by the operating speed
4.6
longitudinal friction coefficient
LFC
ratio between horizontal force (drag) and vertical force (load) for a braked wheel in controlled conditions,
which is normally a decimal number quoted to two significant figures
Note 1 to entry: LFC varies depending on the slip ratio of the device and the operational speed.
4.7
skid resistance
characterisation of the friction of a road surface when measured in accordance with a standardised method
4.8
wet 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 1 to entry: Factors that contribute to skid resistance include the tyre pressure, contact area, tread pattern, and
rubber composition; the alignment, texture, surface pollution, and characteristics of the road surface; the vehicle speed;
and the weather conditions.
The change in skid resistance of a surface in service is affected by the volume of traffic and the composition of the traffic,
as the tyres of these vehicles polish and/or wear away the surfacing material in different ways. Rubber debris especially
affects wet skid resistance.
Where the surface contains aggregate with a coating of binder, e.g. bitumen, resin or Portland cement, the skid resistance
will change as the coating is worn away by tyres.
4.9
fixed slip
condition in which a braking system forces the test wheel to roll at a fixed reduction of its operating speed
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4.10
fixed slip friction
friction between a test tyre and a airfield surface when the wheel is controlled to move at a fixed proportion of
its natural speed
4.11
longitudinal friction coefficient IMAG (LFCI)
ratio between the horizontal force in the direction of the motion that can be activated between the test wheel
and the wet pavement and the vertical wheel force accomplished under controlled slipping conditions
Note 1 to entry: The controlled slipping condition of the test wheel is achieved by a hydraulic pump and a hydraulic
servo-valve enslaved by the sensors of the IMAG.
4.12
sampling length or sampling interval
distance over which responses of the sensors are sampled to determine a single measurement of the
recorded variables
Note 1 to entry: The sampling length depends upon the detailed operation of device and its recording system; a
number of samples may be combined to determine a measurement for a subsection.
Note 2 to entry: This should not be confused with horizontal resolution which is the shortest distance over which a
change in the measured parameter can be detected.
4.13
microtexture
deviation of a pavement from a true planar pavement with characteristic dimensions along the pavement of
less than 0,5 mm, corresponding to texture wavelengths with one-third-octave bands and up to 0,5 mm centre
wavelengths
Note 1 to entry: Peak to peak amplitudes normally vary in the range 0,001 mm to 0,5 mm.
Note 2 to entry: Microtexture is a primary component in skid resistance at low speeds. Those devices that utilise a
relatively low slip speed primarily measure the component of friction affected by microtexture.
4.14
macrotexture
deviation of a pavement from a true planar pavement with characteristic dimensions along the pavement of
0,5 mm to 50 mm, corresponding to texture wavelengths with one-third-octave bands including the range
0,63 mm to 50 mm centre wavelengths
Note 1 to entry: Peak to peak amplitudes normally vary in the range 0,1 mm to 20 mm.
Note 2 to entry: Macrotexture is a major factor influencing skid resistance at high speeds but it also has an effect at
low speeds.
4.15
mean profile depth
descriptor of macrotexture, obtained from a texture profile measurement as defined in EN ISO 13473-1 and
ISO 13473-2
4.16
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 1 to entry: The calibration method for IMAG is given in Clause 10.
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4.17
repeatability
r
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 %
4.18
reproducibility
R
maximum difference expected between two measurements made by different machines with different tyres
using different crews on the same section of roa
...