ASTM_E_1859_-_E_1859M_-_11e1.pdf

Designation:E1859/E1859M111Standard Test Method forFriction Coefficient Measurements Between Tire andPavement Using a Variable Slip Technique1This standard is issued under the fixed designation E1859/E1859M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorially corrected units of measure formatting in November 2013.1.Scope1.1 This test method covers the measurement of the longi-tudinal friction coefficient with a measurement device thatimposes braking-slip between a tire and a surface for the fullrange of braking-slip speed values.1.2 This test method utilizes a series of incremental singlemeasurements of friction force on a braked test wheel as it ispulled over a wetted or contaminated pavement surface.Therotational velocity of the braked wheel is feedback controlledin order to give a predetermined variable slip ratio gradient inaccordance with set program parameters.The test wheel is keptunder a constant static normal load and at a constant longitu-dinal speed of travel.Its major plane is perpendicular to theroad plane and parallel to its direction of motion.1.3 The values measured represent the friction propertiesobtained with the equipment and procedures stated in this testmethod and do not necessarily agree or correlate directly withthose obtained by other pavement friction measuring methods.1.4 The values are intended for use in:1.4.1 Evaluating the braking friction forces on a pavementrelative to that of other pavements.1.4.2 Evaluating changes in the braking friction forces of aparticular pavement with the passage of time.1.4.3 Evaluating the changes in the braking friction force ofa pavement when subjected to polishing wear and loss ofmacrotexture caused by traffic with passage of time.1.4.4 Evaluating changes in the braking friction forces of apavement contaminated with ice,moderate amounts2of slushand snow,pollen,vehicle oil spills and condensates fromvehicle engine exhaust,and deposits from other pollutionsources.1.4.5 Evaluating the braking friction forces of a specimentire on a clean or contaminated pavement.1.5 The friction values reported by this test method areinsufficient to determine the distance required to stop a vehicleon either a dry,wet,or contaminated pavement.They are alsoinsufficient for determining the speed at which control of avehicle would be lost.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in Section 6 and Note 4.2.Referenced Documents2.1 ASTM Standards:3E178 Practice for Dealing With Outlying ObservationsE274 Test Method for Skid Resistance of Paved SurfacesUsing a Full-Scale TireE501 Specification for Rib Tire for Pavement Skid-Resistance TestsE524 Specification for Smooth Tire for Pavement Skid-Resistance TestsE867 Terminology Relating to Vehicle-Pavement SystemsE1136 Specification for P195/75R14 Radial Standard Refer-ence Test TireE1551 Specification for Special Purpose,SmoothTreadTire,Operated on Fixed Braking Slip Continuous FrictionMeasuring Equipment1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.21 onField Methods for Measuring Tire Pavement Friction.Current edition approved Jan.1,2011.Published March 2011.Originallyapproved in 1997.Last previous edition approved in 2006 as E1859 97(2006).DOI:10.1520/E1859_E1859M-11E01.2Slush thickness less than 25 mm 1 in.Loose snow thickness less than 50 mm2 in.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 F377 Practice for Calibration of Braking/Tractive MeasuringDevices for Testing Tires3.Terminology3.1 The terminology used in this test method conforms tothe terminology included in Terminology E867.3.2 Definitions of Terms Specific to This Standard:3.2.1 peak slip friction number,nthe maximum value ofthe slip friction number.3.2.1.1 DiscussionThe peak slip friction number is writtenas SFNpeak(s)where s is the