1、Designation: E 1845 01 (Reapproved 2005)e1Standard Practice forCalculating Pavement Macrotexture Mean Profile Depth1This standard is issued under the fixed designation E 1845; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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.e1NOTEDeleted Footnote 5, as it was no longer relevant, in October 2005.1. Scope1.1 This practice covers the calculation of
3、mean profiledepth from a profile of pavement macrotexture.1.2 The mean profile depth has been shown to be useful inpredicting the speed constant (gradient) of wet pavementfriction.21.3 A linear transformation of the mean profile depth canprovide an estimate of the mean texture depth measuredaccordin
4、g to Test Method E 965.1.4 The values stated in SI (metric) units are to be regardedas standard.The inch-pound equivalents are rationalized, ratherthan exact mathematical conversions.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is there
5、sponsibility 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.2. Referenced Documents2.1 ASTM Standards:3E 965 Test Method for Measuring Pavement MacrotextureDepth Using a Volumetric Technique2.
6、2 ISO Standard:ISO 13473-1 AcousticsCharacterization of PavementTexture using Surface ProfilesPart 1: Determination ofMean Profile Depth43. Terminology3.1 Definitions:3.1.1 baselength, nthe length of a segment of a pavementmacrotexture profile being analyzed, required to be 100 mm inthis practice.3.
7、1.2 estimated texture depth (ETD), nthe estimate of themean texture depth (MTD), by means of a linear transforma-tion of the mean profile depth (MPD).3.1.3 mean profile depth (MPD), nthe average of all themean segment depths of all of the segments of the profile.3.1.4 mean segment depth, nthe averag
8、e value of theprofile depth of the two halves of a segment having a givenbaselength.3.1.5 mean texture depth (MTD), nthe mean depth of thepavement surface macrotexture determined by the volumetrictechnique of Test Method E 965.3.1.6 profile depth (PD), nthe difference between theamplitude measuremen
9、ts of pavement macrotexture and ahorizontal line through the top of the highest peak within agiven baselength.4. Summary of Practice4.1 This practice uses a measured profile of the pavementmacrotexture.4.2 The measured profile is divided for analysis purposesinto segments each having a baselength of
10、 100 mm (3.9 in.).The slope, if any, of each segment is suppressed by subtractinga linear regression of the segment. The segment is furtherdivided in half and the height of the highest peak in each halfsegment is determined. The difference between that height and1This practice is under the jurisdict
11、ion of Committee E17 on Vehicle-PavementSystems and is the direct responsibility of Subcommittee E17.23 on SurfaceCharacteristics Related to Tire Pavement Slip Resistance.Current edition approved Oct. 1, 2005. Published February 2006. Originallyapproved in 1996. Last previous edition approved in 200
12、1 as E 1845 01.2Wambold, J. C., Antle, C. E., Henry, J. J., and Rado, Z., International PIARCExperiment to Compare and Harmonize Texture and Skid Resistance Measure-ments, Final report, Permanent International Association of Road Congresses(PIARC), Paris 1995.3For referenced ASTM standards, visit th
13、e 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.4Available from International Organization for Standardization, 1, rue deVarembe, Case Postale 56, CH
14、-1211 Geneva 20, Switzerland.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the average level of the segment is calculated. The averagevalue of these differences for all segments making up themeasured profile is reported as the MPD.
15、5. Significance and Use5.1 This practice is suitable for the calculation of theaverage macrotexture depth from profile data. The results ofthis calculation (MPD) have proven to be useful in theprediction of the speed dependence of wet pavement friction.25.2 The MPD can be used to estimate the result
16、 of ameasurement of macrotexture depth using a volumetric tech-nique according to E 965. The values of MPD and MTD differdue to the finite size of the glass spheres used in the volumetrictechnique and because the MPD is derived from a two-dimensional profile rather than a three-dimensional surface.T
17、herefore a transformation equation must be used.5.3 This practice may be used with pavement macrotextureprofiles taken on actual road surfaces or from cores orlaboratory prepared samples.5.4 Aggregate size, shape, and distribution are featureswhich are not addressed in this practice. This practice i
18、s notmeant to provide a complete assessment of texture character-istics. In particular, care should be used when interpreting theresult for porous or grooved surfaces.5.5 This practice does not address the problems associatedwith obtaining a measured profile. Laser or other opticalnoncontact methods
19、 of measuring profiles are usually pre-ferred. However, contact methods using a stylus also canprovide accurate profiles if properly performed.6. Profile Requirements6.1 Amount of Data Required:6.1.1 Ideally, a continuous profile made along the entirelength of the test section should be utilized if
20、possible.6.1.2 A minimum requirement shall be ten evenly spacedprofiles of 100 mm (3.9 in.) in length for each 100 m (3900 in.)of the test section. However, for a uniform test section, it issufficient to obtain 16 evenly spaced profiles regardless of testsection length. For surfaces having periodic
21、texture (that is,grooved or tined surfaces) the total profile length shall includeat least ten periods of the texture.NOTE 1When characterizing a long test section with relatively shortsample lengths, it is important to ensure that the texture is sufficientlyhomogeneous to provide a representative m
22、easure. It is necessary for theuser to use sound judgment to determine the minimum number of samplesto characterize a nonhomogeneous pavement.NOTE 2The texture of pavements that have been in service variesacross the pavement. In this case the transverse location of the measure-ments shall be determi
23、ned by the intended use of the data.6.1.3 In the case of laboratory samples (either cores orrectangular slabs) the minimum requirement shall be at leastten profiles having a length of 100 mm (3.9 in.) evenlydistributed over the surface of the sample. Care should be takento avoid edge effects. For th
24、is reason, samples having acharacteristic length of at least 150 mm (5.9 in.) are recom-mended.NOTE 3Measurements on laboratory samples have many differentpurposes. Therefore it is difficult to specify general minimum require-ments. The specification here assumes that the purpose is to obtain values
25、which are reasonably representative of pavements.6.2 Resolution:6.2.1 Vertical resolution shall be at least 0.05 mm (0.002 in).Vertical range shall be no less than 20 mm (0.75 in.) andvertical nonlinearity shall be no greater than 2 % of the range.NOTE 4For stationary devices on smooth pavements a l
26、esser rangemay be used. In this case, non-linearity need not exceed the aboverequirement of 0.4 mm (0.015 in.). The higher range is usually required toallow for a sensor mounted on a moving vehicle.6.2.2 Maximum spot size for a laser or other electro-opticaldevice shall be no greater than 1 mm (0.04
27、 in.). The stylus ina contact device shall have a tip having a major diameter nogreater than 1 mm (0.04 in.).6.2.3 The sampling interval shall not be more than 1 mm(0.04 in.). Variations of the sampling interval shall not be morethan 610 %. This requires that the sensor speed over thesurface be main
28、tained within 610 % whether the device isstationery or mounted on a moving vehicle.6.3 The angles between the radiating emitting device andthe surface and between the radiation receiving device and thesurface shall be no more than 30. The angle of the stylusrelative to the surface shall be no more t
29、han 30. Larger angleswill underestimate deep textures.6.4 Calibration shall be made using calibration surfaceshaving a known profile.The vertical accuracy of the calibrationsurface in relation to its theoretical profile shall be at least 0.05mm (0.002 in.). The calibration shall be designed to provi
30、de amaximum error of 5 % or 0.1 mm (0.004 in.), whichever islower.NOTE 5One suitable calibration surface is a surface machined toobtain a triangular profile with a peak-to-peak amplitude of 520 mm(0.20.75 in.). This gives an indication of not only the amplitude, but alsothe nonlinearity and the text
31、ure wavelength scale.7. Data Processing7.1 OutliersInvalid readings may be caused by dropoutsas a result of deep surface troughs or local photometricproperties of the surface. For this reason, those readings shouldbe eliminated when their value is higher or lower than therange of the profile surroun
32、ding their location. The invalidvalue for that location shall be replaced with a value interpo-lated between the previous and following location. The maxi-mum proportion of outliers shall be 20 %. When the proportionexceeds 10 %, caution should be used in interpreting the dataand the proportion of i
33、nvalid readings shall be reported.7.2 Lowpass FilteringIn order to reduce the influence ofnoise and transients and to have a relatively uniform influenceof narrow profile peaks, the profile shall be filtered to removehigh frequency components. Spatial frequency componentsabove 400 cycles per metre (
34、10 cycles per in.) which corre-sponds to a texture wavelength of 2.5 mm (0.1 in.) shall beremoved. Spatial frequencies below 200 cycles per metre (5cycles per in.) which correspond to a texture wavelength of 5mm (0.2 in.) shall not be affected by the filter.Attenuation shallbe at least 3 dB at 2.5 m
35、m (0.1 in.) and no more than 1 dBat 5 mm (0.2 in.) with a slope of at least 6 dB per octave. Thefiltering may be achieved with a digital filter or with anE 1845 01 (2005)e12electronic filter. All or part of the filtering may be achieved bythe effect of the finite size of the sensor spot or stylus ti
36、p.7.3 Segmenting the ProfileThe measured profile shall bedivided into segments of 100 6 2mm(46 .075 in.) foranalysis in the subsequent steps of this practice. See Fig. 1.7.4 Slope SuppressionA linear regression of the profilevalues for each segment shall be performed and the regressionline shall be
37、subtracted from the profile values of the segment.This will produce a segment with a zero mean and suppress theslope of the segment, if any.7.5 Peak DeterminationEach segment shall be furtherdivided into two equal lengths of 50 mm (2 in.) and themaximum value of the profile shall be determined for e
38、ach ofthe 50 mm (2 in.) subsegments. These two values shall beaveraged arithmetically to obtain the mean segment depth. SeeFig. 1.NOTE 6Some devices invert the profile so that it is necessary toensure that the profile for the segment being analyzed has the peaks asthose asperities with the highest p
39、ositive value.7.6 Determination of MPDThe average value of the meansegment depths for all segments of the measured profile shallbe averaged to obtain the mean profile depth (MPD).7.7 Calculation of ETD (optional)The MPD may betransformed to an estimated texture depth (ETD) by one of thefollowing tra
40、nsformation equations:2ETD 5 0.2 1 0.8 MPD (1)where:MPD and ETD are expressed in mm or:ETD 5 0.008 1 0.8 MPD (2)where:MPD and ETD are expressed in inches.The use of this transformation should yield ETD valueswhich are close to the MTD values of the volumetric techniqueaccording to Test Method E 965.
41、8. Report8.1 The test report for each test surface shall contain thefollowing items:8.1.1 Date of profile measurement,8.1.2 Location and identification of the test surface,8.1.3 Description of the surface type,8.1.4 Description of surface contamination which could notbe avoided by cleaning, includin
42、g moisture,8.1.5 Observations of surface condition such as excessivecracking, potholes, etc.,8.1.6 The position of the profile on the surface, for examplein relation to the wheel track, etc.,8.1.7 Identification of the profile equipment and its opera-tors,8.1.8 Type and date of calibration,8.1.9 Mea
43、surement speed,8.1.10 Percentage of invalid readings eliminated (dropouts),8.1.11 Total profile length and the number of segmentsanalyzed,8.1.12 Mean profile depth (MPD),8.1.13 Standard deviation of the mean segment depthswhich were averaged to obtain the MPD, and8.1.14 The estimated texture depth (
44、ETD)optional.9. Precision and Bias9.1 PrecisionThe reproducibility using two different sys-tems and test crews was found in the same experiment2to be0.15 mm (0.006 in.) corresponding to 10 % of the averageMPD values included in the experiment.FIG. 1 Procedure for Computation of Mean Segment DepthE 1
45、845 01 (2005)e139.2 BiasThere is no basis for determination of the bias inmean profile depth. With respect to the MTD, the MPD isbiased by 0.2 mm (0.008 in.) which is due to the finite size ofthe glass spheres used in the volumetric technique.10. Keywords10.1 macrotexture profile; mean profile depth
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49、to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E 1845 01 (2005)e14
