1、Designation: E 2340 06Standard Test Method forMeasuring the Skid Resistance of Pavements and OtherTrafficked Surfaces Using a Continuous Reading, Fixed-SlipTechnique1This standard is issued under the fixed designation E 2340; the number immediately following the designation indicates the year oforig
2、inal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the skidresistance
3、of a pavement or other trafficked surface using thecontinuous reading, fixed-slip technique.1.2 This test method covers braked wheel measurementsobtained with less than 100 % slip. It does not cover side forcemeasurements.1.3 This test method provides a record of the skid resistancealong the whole l
4、ength of one track of the test surface andenables averages to be obtained for specified test segments.1.4 This test method is used to measure skid resistance on awide variety of surfaces in a wide variety of circumstances.Consequently, there are many different designs of continuousreading, fixed-sli
5、p measuring equipment (CFME) and as manydifferent test procedures governing their use.1.5 This test method does not attempt to detail thesedifferent equipments and procedures but does set out theessential common principles.1.6 CFMEs function by creating and measuring a frictionalforce between a test
6、 tire operating at a selected slip and the testsurface. Different types of CFME do not necessarily create thesame frictional force between their particular test tire and acommon test surface and do not necessarily use the samemethod to measure this frictional force.1.7 CFME measurements are obtained
7、 at a selected steadytest speed. This speed may vary according to the application.1.8 The test surface may be contaminated or clean and dry.If it is clean and dry, a measured amount of water is normallydeposited on the surface just in front of the test wheel.1.9 The measuring apparatus may be built
8、into a vehicle,built into a trailer that is towed by a vehicle, or built into adevice that is manually pushed.1.10 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.11 This standard may involve hazardous materials, opera-tions,
9、 and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.Safet
10、y precautionary information is contained in Section 7.2. Referenced Documents2.1 ASTM Standards:2E 178 Practice for Dealing With Outlying ObservationsE 501 Specification for Rib Tire for Pavement Skid-Resistance TestsE 524 Specification for Smooth Tire for Pavement Skid-Resistance TestsE 867 Termino
11、logy Relating to Vehicle-Pavement SystemsE 1551 Specification for Special Purpose, SmoothTreadTire, Operated on Fixed Braking Slip Continuous FrictionMeasuring EquipmentE 1844 Specification for A Size 10 3 45 Smooth-TreadFriction Test TireF 408 Test Method for Tires for Wet Traction in Straight-Ahea
12、d Braking, Using a Towed TrailerF 457 Test Method for Speed and Distance Calibration ofFifth Wheel Equipped With Either Analog or DigitalInstrumentation3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology E 867.3.2 Definitions:3.2.1 braking force, ndynamic instant
13、aneous frictionalforce acting on the test wheel.3.2.2 braking force coeffcient (BFC), nappropriately fil-tered mean of a number of instantaneous friction readings overa defined distance.1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle- Pavement Systems and is the direct r
14、esponsibility of Subcommittee E17.21 onField Methods for Measuring Tire Pavement Friction.Current edition approved Dec. 1, 2006. Published December 2006.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
15、andards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.3 braking slip friction, ntangential force generatedbetween the test tire and the test su
16、rface.3.2.4 braking slip ratio, nratio of relative braking slipcircumferential speed to identical unbraked wheel circumfer-ential speed, usually defined as a percent.3.2.4.1 DiscussionAn equivalent definition is the ratio ofthe relative braking slip velocity to the horizontal velocity ofthe wheel ax
17、le.3.2.5 continuous reading, fixed slip-measuring equipment(CFME), napparatus that can be moved over the test surfaceat the chosen test speed and includes a test wheel, a system forbraking the test wheel, and instrumentation for measuring theresulting frictional force between the test tire and test
18、surface.3.2.6 fixed slip, nbraking system that forces the test wheelto roll at a constant slip or fixed reduction of its free rollingspeed.3.2.7 frictional force, nresistance generated when onesurface moves relative to another with which it is in contact.3.2.8 instantaneous friction reading, nbrakin
19、g force di-vided by load or equivalently divided by torque on the testwheel (generated by braking force) divided by load times tireradius (moment arm).3.2.9 load force, ndynamic instantaneous vertical forceacting on the test wheel.3.2.10 nominal water film thickness, nthickness of thefilm that the w
20、ater application system is designed to createahead of the test tire on an entirely smooth test surface.3.2.11 rate of water flow, nrate at which water is appliedto the test surface in front of the test tire.3.2.12 reporting length, ndefined length over which theBFC is calculated.3.2.13 standard nomi
21、nal water film thickness, nnominalwater film thickness associated with CFME measurements of aparticular type of test application to facilitate comparisonsbetween the results of different tests.3.2.14 standard test speed, nsteady test speed associatedwith CFME measurements of a particular type of tes
22、t applica-tion to facilitate comparisons between the results of differenttests.3.2.15 test speed, nsteady test speed associated withCFME measurements.3.2.16 water application system, nsystem for depositing agiven amount of water in front of the test tire so that it passesbetween the tire contact are
23、a and the test surface.3.3 Definitions of Terms Specific to This Standard:3.3.1 certifying calibration, nverification of test equip-ment, calibration equipment (separate or inbuilt), calibrationprocedures, and equipment operation recommended to becarried out once a year; the procedure records both a
24、s foundvalues and adjusted values.3.3.2 field calibration, nprimary force calibration or theequivalent carried out before each test or series of tests by atrained operator using calibration equipment supplied by themanufacturer; this equipment may be built into the CFME.3.3.3 friction map, npresenta
25、tion of friction readingsobtained down the length of a test surface (typically an airportrunway) over a series of selected paths down the surface.3.3.4 operational friction testing, nmeasurement of thefriction of a surface in response to an operational need and inwhatever conditions exist at the tim
26、e of the test, which mayinclude contamination by ice, snow, slush, or water; these testsdo not include the application of water.3.3.5 routine friction testing, nmeasurement of the fric-tion of a surface under standardized test conditions thatnormally includes a standard test speed and a rate of wate
27、r flowwhich gives a standard nominal water film thickness.3.3.6 test tire, nstandard tire for pavement friction testing;test tires for routine friction testing shall have a smooth tread.4. Summary of Test Method4.1 The test system is moved over the test surface at thechosen test speed with the test
28、wheel, fitted with a test tire, andforced to roll at a particular braking slip ratio.4.2 If routine friction testing is taking place, the rate ofwater flow is adjusted to the test speed so that the chosennominal water film is achieved.4.3 The braking force or torque is measured (see Terminol-ogy E 8
29、67) and the load is measured, calculated, or assumed tobe the same as the dead weight load.4.4 The instantaneous friction reading is calculated.4.5 Either the instantaneous friction reading is recorded orthe BFC for each friction length is calculated and recorded.4.6 Test speed (see Test Method F 45
30、7), rate of water flow,and other essential supporting data are recorded.5. Significance and Use5.1 CFMEs are used to measure skid resistance on runways,roads, and various other trafficked surfaces. These tests maycomprise operational testing, performed to obtain an immedi-ate assessment of skid resi
31、stance in current conditions orroutine testing in standardized conditions which include theapplication of a precise amount of water in front of the test tire.5.2 Standard test speeds and nominal water film thicknessesare according to national or international agency standards, thetype of CFME, and t
32、he test application. Some examples oftypical applications are given in Appendix X1.6. Apparatus6.1 Basic Measurements:6.1.1 The test apparatus shall be equipped with a forcetransducer to provide a direct measurement of the braking forceor a torque transducer to measure the torque on the test wheelge
33、nerated by this force or both.6.1.2 The design of the test apparatus shall ensure thatunless the average load force acting on the test wheel remainswithin 1 % of the static wheel load over the reporting length,the apparatus shall be equipped with a force transducer tomeasure the load force.6.1.3 The
34、 test apparatus shall include a mechanism formeasuring test speed and distance traveled.6.1.4 Unless the test apparatus is to be used solely foroperational testing, it shall include a mechanism for measuringrate of water flow.6.2 Tolerance for Adverse Conditions:6.2.1 The exposed portions of the sys
35、tem shall tolerate100 % relative humidity (RH) (rain or spray) and all otherE2340062adverse conditions, such as de-icing chemicals, dust, shock,and vibrations that may be encountered in the type of testingfor which the equipment is designed. The suspension systemshall minimize the influence of norma
36、l pavement roughness onthe accuracy and fidelity of the data collection.6.3 Accuracy, Resolution, and Stability of Measuring Sys-tem:6.3.1 At outside ambient air temperatures between 40 and45C (40 and 110F), overall static system measurementaccuracy shall be 61.5 % of full scale.6.3.2 Certifying cal
37、ibration or other time stability calibra-tion shall not be required more than once a year unless themeasuring system sustains damage requiring significant repair.6.3.3 If there is a force transducer that provides a directmeasurement of the braking force, it shall do so with minimalinertial effects.
38、It is recommended that this transducer providesoutput directly proportional to force with hysteresis less than1 % of the applied load up to the maximum expected loading.The mounting of the braking force-measuring transducer shallbe such that the effects of cross-axle loading or torque loadingshall b
39、e less than 1 % of the applied load. The braking forcetransducer shall be mounted in such a manner as to experienceless than 1 angular rotation with respect to its longitudinalmeasuring plane at the maximum expected loading.6.3.4 If there is a torque transducer that measures the torqueon the test wh
40、eel generated by the braking force, this shallprovide output directly proportional to torque with hysteresisless than 1 % of the applied load and nonlinearity up to themaximum expected loading less than 1 % of the applied load.The sensitivity to any cross-axis loading shall be less than 1 %of the ap
41、plied load. Torque transducer measurements includerolling tire/wheel inertial effects, which shall be compensatedfor at all test speeds.6.3.5 If the load force is measured, the accuracy of themeasurement shall conform to the requirements set out in6.3.3. If the load force is assumed constant, it sha
42、ll be possibleto show that the assumed dynamic wheel load is within 62%of the actual dynamic wheel load.6.3.6 Distance shall be measured with a resolution of 0.1 %and an accuracy of 60.5 % and shall be continuously recorded.6.3.7 Speed shall be measured with a resolution of 2 kmh (1mph) and an accur
43、acy of 61 kmh (60.5 mph). It is recom-mended that these measurements be continuously recorded.6.4 Braking Slip:6.4.1 The test apparatus shall be such that the chosen fixedbraking slip can be maintained within 63 % of full scalethroughout the length of the test surface at the chosen testspeed (for ex
44、ample, if the chosen fixed braking slip is 15 %, abraking slip between 12 and 18 % shall be maintained).6.5 Test SpeedWith the test tire operating at the chosenfixed braking slip, the test apparatus shall be capable ofmaintaining the chosen test speed within 63 % for the durationof the survey.6.6 Te
45、st TireThe test tire shall conform to the applicableASTM, ISO, or BSI specification or equivalent. ApplicableASTM standards include Specifications E 501, E 524, E 1551and E 1844.6.7 Water Application System:6.7.1 Water shall be applied to the test surface just ahead ofthe test tire so as to provide
46、the chosen nominal water filmthickness across the full width of the test tire at any test speed.6.7.2 The water application system shall be protected fromthe effects of side winds, either by use of a flexible nozzle veryclose to the test surface or by shielding the nozzle in some wayor by using a je
47、t of water with horizontal speed equal andopposite to the test speed and applied slightly wider than thewidth of the test tire tread.6.7.3 Water used for testing shall be reasonably clean andhave no chemicals such as wetting agents or detergents addedand shall not be above 30C (86F).6.7.4 The nomina
48、l water film thickness shall be in accor-dance with the manufacturers handbook and the test applica-tion.6.7.5 Rate of water flow shall be continuously measured andit is recommended that it be continuously recorded.6.7.6 Regulation of rate of water flow shall be within610 %.6.8 Signal-Conditioning a
49、nd Recording Systems:6.8.1 All signal-conditioning and recording equipment shallprovide linear output and allow data reading resolution to meetthe requirements of 6.3.All systems except the smoothing filterdescribed in 6.8.3 shall provide a minimum bandwidth of atleast 0 to 20 Hz (flat within 61 %).6.8.2 Measurements shall be recorded in phase and all forcesignals shall be referenced to a common time base and bepassed through the same filter.6.8.3 A low-pass electronic filter, typically between 4.8Hz/-3db/4 pole and a 10 Hz/-3db/8 pole, shall be insta
