1、Designation: E2380/E2380M 09Standard Test Method forMeasuring Pavement Texture Drainage Using an OutflowMeter1This standard is issued under the fixed designation E2380/E2380M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the yea
2、r 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.1. Scope1.1 This test method covers the connectivity of the textureas it relates to the drainage capability of the pavement t
3、hroughits surface and subsurface voids. This is a specific device thattimes how long it takes a known quantity of water, undergravitational pull, to escape through voids in the pavementtexture of the structure being tested. The technique is intendedto provide a measure of the ability of the pavement
4、 to relievepressure from the face of vehicular tires and thus an indicationof hydroplaning potential under wet conditions.Afaster escapetime indicates a thinner film of water may exist between the tireand the pavement, thus more micro-texture could be exposed toindent the face of the tire and more s
5、urface friction available tothe tire. The lower the number of seconds it takes to evacuatethe water, the lower the water pressure under the tire. It will beup to the operator to compare the results of this test to otherpertinent factors such as expected rainfall intensity and fre-quency, aggregate t
6、ype, consistency of texture, grade, slope,expected vehicular speed, and accident history, to determinethe relationship between the outflow meter reading and thelikelihood of hydroplaning on a given surface. Comparing theoutflow meter reading of a pavement known to have a historyof hydroplaning, agai
7、nst one with a good history, with all otherfactors similar, will give the operator an indication of theoutflow meter number that will be necessary to promote wetweather safety.1.2 The results obtained using this test method are related tothe mean hydraulic radius of a paved surface and may correlate
8、with other methods to measure texture.1.3 The results obtained using this test method are related tothe mean texture depth (MTD).1.4 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; theref
9、ore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.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
10、 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:2E178 Practice for Dealing With Outlying ObservationsE867 Terminology Relating to Vehicle-Pavement SystemsE965 Test Method for Meas
11、uring Pavement MacrotextureDepth Using a Volumetric TechniqueE1845 Practice for Calculating Pavement MacrotextureMean Profile DepthE2157 Test Method for Measuring Pavement MacrotextureProperties Using the Circular Track Meter3. Terminology3.1 For definitions of terms, see Terminology E867.4. Summary
12、 of Test Method Operations4.1 The main body of the outflow meter is a verticalcylinder for containing water. It has an open top and a rubberring mounted centrally around an orifice or opening on thebottom of the device to form a seal against the pavementsurface. Water discharge is through the openin
13、g in the center ofthe seal and is controlled by a spring-loaded plunger suspendedfrom a cap mounted on the upper end of the cylinder. Upperand lower float switches are suspended from the cap into thecylinder and mounted vertically. An electronic timer is pro-vided and is wired to the float switches.
14、4.2 The outflow meter is placed on the pavement with theplunger sealing the water discharge opening. Sufficient water isthen poured into the cylinder to raise the switch floats to theirraised or top position, which will prevent the timer fromoperating. The timer is reset to zero and the plunger is r
15、eleasedto allow discharge of the water. As water flows out of theopening and through the pavement voids, the water level in the1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle- Pavement Systems and is the direct responsibility of Subcommittee E17.23 onSurface Characterist
16、ics Related to Tire Pavement Slip Resistance.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 2005. Last previous edition approved in 2005 as E238005. DOI:10.1520/E2380_E2380M-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
17、 Customer Service at serviceastm.org. For Annual Book of ASTMStandards 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.cylinder falls past the upper
18、float switch, which activates,causing the electronic timer to begin counting. As the waterlevel continues to fall past the level of the lower float switch,the lower float switch then activates, causing the timer to stop.The time required for the water level in the cylinder to fall fromthe level of t
19、he upper float switch to the level of the lower floatswitch is indicated on the timer. This is recorded as the outflowtime.4.3 Calibrations over a temperature range of 40 to 120F 4to 49C show no temperature affects.5. Significance and Use5.1 This test method is suitable as a field test to evaluate t
20、hesurface drainage, and in some cases, the internal drainage ofthe surface course of a pavement. When used with other tests,the outflow time may be used to evaluate the texture producedby an asphalt concrete mix, a finishing method used onPortland cement concrete pavement, and refinishing operations
21、on an old pavement surface. Test results will correlate withother methods such as the CTMeter (Test Method E2157),MPD (Practice E1845), and MTD (Test Method E965).NOTE 1The reciprocal of the outflow time is highly correlated withthe MPD except when the surface is highly porous since the MPD is ameas
22、ure of the surface texture and does not account for the water flowingthrough the surface pores.5.2 The outflow times measured by this method are anindication only, and are not meant to provide a completeassessment of the pavement surface friction, or wet weathersafety characteristics.5.3 This test m
23、ethod does not necessarily correlate or agreewith other methods of measuring pavement surface character-istics. It is up to the operator to determine the correlation ofeach method considered.6. Apparatus and Materials6.1 The essential elements of the apparatus, shown in Fig. 1,consists of the follow
24、ing:6.1.1 Upper and Lower Float SwitchSuspended from acap into the cylinder.6.1.2 PlungerSuspended from a cap mounted on theupper end of the cylinder.6.1.3 Rubber Sealing RingThe sealing rings shall bemade of neoprene rubber and have a durometer level of 70 65.6.1.4 TimerAn electrical timer with at
25、least a three-digitdisplay indicating the elapsed time to the nearest 1.0 s, or incase of calibration or research to 0.01 s or better.6.1.5 WaterWater shall be clean and have no wettingagents or detergents added, and when calibrated, distilled watershall be used.6.1.6 BrushesA broom or a hand-held w
26、ire brush shall beused to clean the test area, if needed.7. Calibration7.1 Calibration of the outflow meter is as follows:7.1.1 Water volume shall be no less than 650 cc 39.7 cu in.and no greater than 700 cc 42.7 cu in.7.1.2 Outlet orifice shall be made of synthetic sapphirematerial.7.1.3 The bore d
27、iameter shall be 4.877 6 0.0254 mm 0.1926 0.001 in.7.1.4 The bore length shall be 2.54 6 0.00254 mm 0.100 60.0001 in.7.1.5 Bore concentricity within 0.0508 mm 0.002 in.7.1.6 Edge sharpness within 0.0508 mm 0.002 in.7.1.7 Bore finish to 50.8 m 2 in.7.1.8 Bottom seal thickness shall be no less than 6
28、mm0.2362 in. or more than 7 mm 0.2756 in.7.1.9 Bottom seal ID shall be no less than 60 mm 2.362 in.or more than 65 mm 2.559 in.7.1.10 Bottom seal OD shall be no less 100 mm 3.937 in.or more than 105 mm 4.134 in.7.1.11 Bottom seal shall be neoprene rubber with a 70 6 5durometer.7.1.12 Lower switch sh
29、all contact at 89.9 to 101.6 mm 3.50to 4 in. from the lower extremities of the bottom seal.7.1.13 Upper switch shall contact at 190.5 to 203.2 mm7.50 to 8 in. from the lower extremities of the bottom seal.7.1.14 A 4.877-mm 0.192-in. wire lapped orifice shall beput in a 4-mm 0.16-in. thick flat metal
30、 plate for sealingpurposes. The outflow time must be at least 22 s but less than23 s on five consecutive tests to qualify for calibration status onthe calibration plate. When measuring to11000 of a second, aCV of 0.65 % shall be met.8. Procedure8.1 Test AreaInspect the pavement surface to be measure
31、dand select a homogeneous area that contains no unique,localized features such as paint, holes, bumps, cracks, or joints.If there is any loose or semi-adhered dirt, debris, or deterio-rated surface material, thoroughly clean the pavement surfacein the area where the test is to be taken using a broom
32、 or stiffwire brush. On pavements that have just been under traffic,tests performed without cleaning will give actual drainagecapability.8.2 MeasurementPlace the outflow meter on the pave-ment making sure that it is stable and uniformly contacts therubber sealing ring to the pavement. On the first t
33、est, wet theplunger sealing ring by holding it close to the seat and pour ina little water. Set the plunger by pushing down on the handleuntil the plunger seal enters the seat, and fill the cylinder withwater. For accurate measurement, the water level must extendover the top float switch sufficientl
34、y to allow air bubblestrapped between the pavement surface and the plunger toescape, and the surface water shall have a chance to settledown before the water level reaches the top float switch. Makesure the timer is reset to zero. Carefully pull the plunger upwhile applying an equal counter force do
35、wnward on thehandle. When the plunger seal is released from the seat, thisbecomes a hands-off operation.Aspring will return the plungerto its most upright position. From this point, the outflow meterworks automatically and should not be touched until the test isover. When the lower float switch is a
36、ctivated and the timerstops, the plunger may be reset to save water and be ready tobe filled with water for the next test.After each test, the outflowmeter timer reading and the location of the test should berecorded.E2380/E2380M 0928.3 Number of MeasurementsThe more tests that areperformed, the bet
37、ter the average pavement drainage informa-tion will be. In any case, a minimum of four randomly spacedtests shall be performed and the arithmetic average of the testtimes shall be reported as the average time for the section of thepavement being evaluated.8.4 For each pavement test section, the arit
38、hmetic averageof all outflow meter test times will be determined and recordedto the 0.01 s. The following equation will be used to estimatethe mean texture depth:MTD 5 3.114/OFT 1 0.636 (1)FIG. 1 Outflow MeterE2380/E2380M 093where:MTD = volumetric texture depth defined in TerminologyE867.9. Faulty T
39、ests9.1 Tests that are manifestly faulty, or that give outflowtimes differing by more than 10 s from the average of all testson the same pavement surface, shall be treated in accordancewith Practice E178 on outlying observations.10. Report10.1 The report for each pavement test surface shall containd
40、ata on the following items:10.1.1 Location and identification of test pavement surface,10.1.2 Date,10.1.3 Ambient air temperature,10.1.4 Pavement temperatures (optional),10.1.5 Number of measurements, and10.1.6 Outflow times recorded.11. Precision and Bias11.1 PrecisionThe precision (the standard de
41、viation) ofthe outflow meter that reads only whole seconds is 0.187 s andhas a coefficient variation (CV) of 0.85 % when run on thecalibration plate. The unit that reads to11000 of a second has astandard deviation of 0.143 s (CV of 0.63 %).11.2 BiasBecause the whole second unit truncates, it hasa bi
42、as of 0.6 s as compared to the11000 of a second unit.REFERENCES(1) Wambold, J. C., Antle, C. E., Henry, J. J., and Rado, Z., “InternationalPIARC Experiment to Compare and Harmonize Texture and SkidResistance Measurements,” Final report, Permanent International As-sociation of Road Congresses (PIARC)
43、, Paris, 1995.(2) Abe, H., Henry, J. J., Tamai, A., and Wambold, J. C., “Measurement ofPavement Macrotexture Using the Circular Texture Meter (CTMeter),”Transportation Research Board Annual Meeting, Washington DC,2001.(3) Wambold, J. C. and Henry, J. J., “NASA Wallops Tire/RunwayFriction Workshops 1
44、993-2002,” Report TP 14190E, TransportationDevelopment Centre (TDC) of Transport Canada (TC), September2002.(4) Wambold, J. C., and Henry, J. J., “NASA Tenth Tire/Runway FrictionWorkshop 2003 NASA Wallops Flight Facility,” National Aeronauticsand Space Administration (NASA), September 29 to October
45、3, 2003.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rig
46、hts, 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 not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional
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48、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E2380/E2380M 094
