1、Designation: E1845 15Standard Practice forCalculating Pavement Macrotexture Mean Profile Depth1This standard is issued under the fixed designation E1845; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the calculation of mean profiledepth from a profile of pavement macrotexture.1.2 The mean profile depth has been s
3、hown 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 measuredaccording to Test Method E965.1.4 The values stated in SI units are to be regarded asstandard. No other
4、 units of measurement are included in thisstandard.1.5 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
5、regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E178 Practice for Dealing With Outlying ObservationsE965 Test Method for Measuring Pavement MacrotextureDepth Using a Volumetric Technique2.2 ISO Standard:ISO 13473-1 AcousticsCharacterization of PavementTexture using Sur
6、face ProfilesPart 1: Determination ofMean Profile Depth43. Terminology3.1 Definitions:3.1.1 baselength, nlength of a segment of a pavementmacrotexture profile being analyzed, required to be 100 mm inthis practice.3.1.2 estimated texture depth (ETD), nestimate of themean texture depth (MTD), by means
7、 of a linear transforma-tion of the mean profile depth (MPD).3.1.3 mean profile depth (MPD), naverage of all the meansegment depths of all of the segments of the profile.3.1.4 mean segment depth, naverage value of the profiledepth of the two halves of a segment having a given base-length.3.1.5 mean
8、texture depth (MTD), nmean depth of thepavement surface macrotexture determined by the volumetrictechnique of Test Method E965.3.1.6 profile depth (PD), ndifference between the ampli-tude measurements of pavement macrotexture and a horizontalline through the top of the highest peak within a givenbas
9、elength.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 100 mm. The slope,if any, of each segment is suppressed by subtracting a linearregression of the segm
10、ent. The segment is further divided inhalf and the height of the highest peak in each half segment isdetermined. The difference between that height and the averagelevel of the segment is calculated. The average value of thesedifferences for all segments making up the measured profile isreported as t
11、he MPD.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
12、 result of ameasurement of macrotexture depth using a volumetric tech-nique according to Test Method E965. The values of MPD and1This practice is under the jurisdiction of Committee E17 on Vehicle - PavementSystems and is the direct responsibility of Subcommittee E17.23 on SurfaceCharacteristics Rel
13、ated to Tire Pavement Slip Resistance.Current edition approved May 1, 2015. Published June 2015. Originallyapproved in 1996. Last previous edition approved in 2009 as E1845 09. DOI:10.1520/E1845-15.2Wambold, J. C., Antle, C. E., Henry, J. J., and Rado, Z., International PIARCExperiment to Compare an
14、d Harmonize Texture and Skid ResistanceMeasurements, Final report, Permanent International Association of Road Con-gresses (PIARC), Paris 1995.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
15、lume information, refer to the standards Document Summary page onthe ASTM website.4Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.Copyright ASTM International, 100 Barr Harbor Drive, PO
16、Box C700, West Conshohocken, PA 19428-2959. United States1MTD differ due to the finite size of the glass spheres used in thevolumetric technique and because the MPD is derived from atwo-dimensional profile rather than a three-dimensional sur-face. Therefore a transformation equation must be used.5.3
17、 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 is notmeant to provide a complete assessment of text
18、ure 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 of measuring profiles are usually pre-ferred. Howe
19、ver, 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 used if possible.6.1.2 A minimum requirement shall be ten evenl
20、y spacedprofiles of 100 mm in length for each 100 m of the test section.However, for a uniform test section, it is sufficient to obtain 16evenly spaced profiles regardless of test section length. Forsurfaces having periodic texture (that is, grooved or tinedsurfaces) the total profile length shall i
21、nclude at least tenperiods of the texture.NOTE 1Inspect the pavement surface to be measured and ensure thatit is dry.When possible, thoroughly clean the surface using compressed airor a soft-bristle brush, or both, in order to remove any visible residue,debris, or loose aggregate particles from the
22、surface. When characterizinga long test section with relatively short sample lengths, it is important toensure that the texture is sufficiently homogeneous to provide a represen-tative measure. It is necessary for the user to use sound judgment todetermine the minimum number of samples to characteri
23、ze a nonhomo-geneous 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 determined by the intended use of the data.6.1.3 In the case of laboratory samples (either cores orrectangular slabs) t
24、he minimum requirement shall be at leastten profiles having a length of 100 mm evenly distributed overthe surface of the sample. Care should be taken to avoid edgeeffects. For this reason, samples having a characteristic lengthof at least 150 mm are recommended.NOTE 3Measurements on laboratory sampl
25、es have many differentpurposes. Therefore it is difficult to specify general minimum require-ments. The specification here assumes that the purpose is to obtain valueswhich are reasonably representative of pavements.6.2 Resolution:6.2.1 Vertical resolution shall be at least 0.05 mm. Verticalrange sh
26、all be no less than 20 mm and vertical nonlinearityshall be no greater than 2 % of the range.NOTE 4For stationary devices on smooth pavements a lesser rangemay be used. In this case, non-linearity need not exceed the aboverequirement of 0.4 mm. The higher range is usually required to allow fora sens
27、or 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. The stylus in a contactdevice shall have a tip having a major diameter no greater than1 mm.6.2.3 The sampling interval shall not be more than 1 mm.Variations of the sampli
28、ng interval shall not be more than610 %. This requires that the sensor speed over the surface bemaintained within 610 % whether the device is stationery ormounted on a moving vehicle.6.3 The angles between the radiating emitting device andthe surface and between the radiation receiving device and th
29、esurface shall be no more than 30. The angle of the stylusrelative to the surface shall be no more than 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
30、theoretical profile shall be at least 0.05mm. The calibration shall be designed to provide a maximumerror of 5 % or 0.1 mm, whichever is lower.NOTE 5One suitable calibration surface is a surface machined toobtain a triangular profile with a peak-to-peak amplitude of 5 to 20 mm.This gives an indicati
31、on of not only the amplitude, but also the nonlin-earity and the texture 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 whe
32、n their value is higher or lower than therange of the profile surrounding 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 %, c
33、aution should be used in interpreting the dataand the proportion of invalid readings shall be reported. UsePractice E178 to determine what data is to be considered anoutlier.7.2 Lowpass FilteringTo reduce the influence of noise andtransients and to have a relatively uniform influence of narrowprofil
34、e peaks, the profile shall be filtered to remove highfrequency components. Spatial frequency components above400 cycles per metre that correspond to a texture wavelength of2.5 mm shall be removed. Spatial frequencies below 200 cyclesper metre that correspond to a texture wavelength of 5 mmshall not
35、be affected by the filter. Attenuation shall be atleast 3 dB at 2.5 mm and no more than 1 dB at 5 mm witha slope of at least 6 dB per octave. The filtering may beachieved with a digital filter or with an electronic filter. All orpart of the filtering may be achieved by the effect of the finitesize o
36、f the sensor spot or stylus tip.7.3 Segmenting the ProfileThe measured profile shall bedivided into segments of 100 6 2 mm for analysis in thesubsequent steps of this practice. See Fig. 1.7.4 Slope SuppressionA linear regression of the profilevalues for each segment shall be performed and the regres
37、sionline shall be subtracted from the profile values of the segment.E1845 152This 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 and the maximumvalue of the profile shall
38、be determined for each of the 50-mmsubsegments. These two values shall be averaged arithmeti-cally to obtain the mean segment depth. See Fig. 1.NOTE 6Some devices invert the profile so that it is necessary to ensurethat the profile for the segment being analyzed has the peaks as thoseasperities with
39、 the highest positive 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 use of th
40、efollowing transformation equation:2ETD 5 0.210.8 MPD (1)where:MPD and ETD are expressed in mm.The use of this transformation should yield ETD values thatare close to the MTD values of the volumetric techniqueaccording to Test Method E965. However, caution should beused in the comparison of ETD (tha
41、t does not capture theconcave recesses of the pavement surface) to MTD (that doescapture the concave recesses in the pavement surface).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 s
42、urface;8.1.3 Description of the surface type;8.1.4 Description of surface contamination that could not beavoided by cleaning, including moisture;8.1.5 Observations of surface condition such as excessivecracking, potholes, and so forth;8.1.6 The position of the profile on the surface, for examplein r
43、elation to the wheel track, and so forth;8.1.7 Identification of the profile equipment and its opera-tors;8.1.8 Type and date of calibration;8.1.9 Measurement 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
44、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 (ETD)optional.9. Precision and Bias9.1 PrecisionThe reproducibility using two different sys-tems and test crews was found in the same experiment2to be0
45、.15 mm corresponding to 10 % of the average MPD valuesincluded in the experiment.9.2 BiasThere is no basis for determination of the bias inmean profile depth. With respect to the MTD, the MPD isbiased by 0.2 mm that is due to the finite size of the glassspheres used in the volumetric technique.10. K
46、eywords10.1 macrotexture profile; mean profile depth; mean texturedepthFIG. 1 Procedure for Computation of Mean Segment DepthE1845 153ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standa
47、rd are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif
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49、ch you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known 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).
