1、Designation: E2380/E2380M 15Standard 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 andfrequency, aggregate typ
6、e, 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, agains
7、t 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 correlatewi
8、th 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; therefor
9、e, 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 t
10、o 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 Measur
11、ing Pavement MacrotextureDepth Using a Volumetric Technique (Withdrawn 2015)3E1845 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
12、 E867.4. Summary 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 th
13、rough the opening 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
14、 float switches.4.2 The outflow meter is placed on the pavement with theplunger sealing the water discharge opening. Sufficient water is1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle- Pavement Systems and is the direct responsibility of Subcommittee E17.23 onSurface Cha
15、racteristics Related to Tire Pavement Slip Resistance.Current edition approved Jan. 1, 2015. Published January 2015. Originallyapproved in 2005. Last previous edition approved in 2009 as E2380/E2380M 09.DOI: 10.1520/E2380_E2380M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org
16、, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor
17、 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1then 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 releasedto allow discharge of the water. As water fl
18、ows out of theopening and through the pavement voids, the water level in thecylinder falls past the upper 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,
19、causing the timer to stop.The time required for the water level in the cylinder to fall fromthe level of the 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
20、 temperature affects.5. Significance and Use5.1 This test method is suitable as a field test to evaluate thesurface 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 asp
21、halt concrete mix, a finishing method used onPortland cement concrete pavement, and refinishing operationson 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 out
22、flow time is highly correlated withthe MPD except when the surface is highly porous since the MPD is ameasure 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
23、 completeassessment of the pavement surface friction, or wet weathersafety characteristics.5.3 This test method 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.
24、Apparatus and Materials6.1 The essential elements of the apparatus, shown in Fig. 1,consists of the following: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 s
25、hall be madeof neoprene rubber and have a durometer level of 70 6 5.6.1.4 TimerAn electrical timer with at 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 o
26、r detergents added, and when calibrated, distilled watershall be used.6.1.6 BrushesA broom or a hand-held wire 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 great
27、er than 700 cc 42.7 cu in.7.1.2 Outlet orifice shall be made of synthetic sapphirematerial.7.1.3 The bore diameter 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 with
28、in 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 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 tha
29、n 105 mm 4.134 in.7.1.11 Bottom seal shall be neoprene rubber with a 70 6 5durometer.7.1.12 Lower switch shall 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
30、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 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
31、of a second, aCV of 0.65 % shall be met.8. Procedure8.1 Test AreaInspect the pavement surface to be measuredand 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 sur
32、face material, thoroughly clean the pavement surfacein the area where the test is to be taken using a broom 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 pavementma
33、king sure that it is stable and uniformly contacts the rubbersealing ring to the pavement. On the first test, wet the plungersealing ring by holding it close to the seat and pour in a littlewater. Set the plunger by pushing down on the handle until theplunger seal enters the seat, and fill the cylin
34、der with water. Foraccurate measurement, the water level must extend over the topfloat switch sufficiently to allow air bubbles trapped betweenthe pavement surface and the plunger to escape, and the surfacewater shall have a chance to settle down before the water levelreaches the top float switch. M
35、ake sure the timer is reset tozero. Carefully pull the plunger up while applying an equalcounter force downward on the handle. When the plunger sealis released from the seat, this becomes a hands-off operation. Aspring will return the plunger to its most upright position. Fromthis point, the outflow
36、 meter works automatically and shouldE2380/E2380M 152not be touched until the test is over. When the lower floatswitch is activated and the timer stops, the plunger may bereset to save water and be ready to be filled with water for thenext test. After each test, the outflow meter timer reading andth
37、e location of the test should be recorded.8.3 Number of MeasurementsThe more tests that areperformed, the better 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 testFIG. 1 Outflow MeterE2380/
38、E2380M 153times shall be reported as the average time for the section of thepavement being evaluated.8.4 For each pavement test section, the arithmetic 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
39、 depth:MTD 5 3.114/OFT10.636 (1)where:MTD = volumetric texture depth as determined by TestMethod E965.9. Faulty Tests9.1 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 accordancewi
40、th Practice E178 on outlying observations.10. Report10.1 The report for each pavement test surface shall containdata 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
41、measurements, and10.1.6 Outflow times recorded.11. Precision and Bias11.1 PrecisionThe precision (the standard deviation) 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 seco
42、nd has astandard deviation of 0.143 s (CV of 0.63 %).11.2 BiasBecause the whole second unit truncates, it hasa bias 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 Textur
43、e and SkidResistance Measurements,” Final report, Permanent InternationalAssociation of Road Congresses (PIARC), Paris, 1995.(2) Abe, H., Henry, J. J., Tamai, A., and Wambold, J. C., “Measurementof Pavement Macrotexture Using the Circular Texture Meter(CTMeter),” Transportation Research Board Annual
44、 Meeting, Wash-ington DC, 2001.(3) Wambold, J. C. and Henry, J. J., “NASA Wallops Tire/RunwayFriction Workshops 1993-2002,” Report TP 14190E, TransportationDevelopment Centre (TDC) of Transport Canada (TC), September2002.(4) Wambold, J. C., and Henry, J. J., “NASA Tenth Tire/Runway FrictionWorkshop
45、2003 NASAWallops Flight Facility,” National Aeronauticsand Space Administration (NASA), September 29 to October 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 express
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