1、Designation: E 2380 05Standard Test Method forMeasuring Pavement Texture Drainage Using an OutflowMeter1This standard is issued under the fixed designation E 2380; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 connectivity of the textureas it relates to the drainage capability of the pavement throughits s
3、urface 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 to relieve
4、pressure 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 surface fric
5、tion 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 type, consis
6、tency 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, against one wit
7、h 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 method are related to themean hydraulic radius of a paved surface and may correlatewith other metho
8、ds 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 SI units are considered standard.This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof
9、the user of this standard to establish limitations prior to use.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 appli
10、ca-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 178 Practice for Dealing with Outlying ObservationsE 867 Terminology Relating to Vehicle-Pavement SystemsE 965 Test Method for Measuring Pavement MacrotextureProperties Using a Volumetric TechniqueE 1845 Pr
11、actice for Calculating Pavement MacrotextureMean Profile DepthE 2157 Test Method for Measuring Pavement MacrotextureProperties Using the Circular Track Meter3. Terminology3.1 For definitions of terms, see Terminology E 867.4. Summary of Test Method Operations4.1 The main body of the outflow meter is
12、 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 opening in the center ofthe seal and is controlled by a spring loaded plu
13、nger 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.4.2 The outflow meter is placed on the pavement with theplunger sea
14、ling 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 releasedto allow discharge of the water. As water flows out of theop
15、ening 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,1This test method is under the jurisdiction of ASTM Com
16、mittee E17 onVehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.23on Surface Characteristics Related to Tire Pavement Slip Resistance.Current edition approved Feb. 1, 2005. Published February 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcont
17、act ASTM 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.the lower float switch
18、 then activates, 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 120
19、F (4to 49C) show no 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 textur
20、e producedby an asphalt pavement mix, a finishing method used onPortland Cement Pavement, and refinishing operations on anold pavement surface. Test results will correlate with othermethods such as the CTMeter (Test Method E 2157), MPD(Practice E 1845) and MTD (Test Method E 965).NOTE 1The reciproca
21、l of the outflow 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
22、to provide a 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 co
23、nsidered.6. 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 sea
24、ling rings shall bemade of neoprene rubber and have a durometer level of 70 65.6.1.4 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 wett
25、ingagents or 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.
26、)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 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.).
27、7.1.6 Edge sharpness within 0.0508 mm (0.002 in.).7.1.7 Bore finish to 2 in.7.1.8 Bottom seal thickness shall be no less than 6 mm(0.2362 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 l
28、ess 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 shall contact at 89.9 mm (3.50 in.) to101.6 mm (4 in.) from the lower extremities of the bottom seal.7.1.13 Upper switch shall contact at 190.5 mm (7.50 in.) t
29、o203.2 mm (8 in.) from the lower extremities of the bottom seal.7.1.14 A 4.877-mm (0.192-in.) wire lapped orifice shall beputina4mmthick flat metal plate for sealing purposes. Theoutflow time must be at least 22 s but less than 23 s on 5consecutive tests to qualify for calibration status on thecalib
30、ration plate. When measuring to11000 of a second, a CV of0.65 % 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-adher
31、ed dirt, debris, or deterio-rated surface 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 MeasurementPlac
32、e 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 test, 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 s
33、eal enters the seat, and fill the cylinder withwater. For accurate measurement, the water level must extendover the top float switch sufficiently to allow air bubblestrapped between the pavement surface and the plunger toescape, and the surface water must have a chance to settledown before the water
34、 level reaches the top float switch. Makesure the timer is reset to zero. Carefully pull the plunger upwhile applying an equal counter force downward on thehandle. When the plunger seal is released from the seat, thisbecomes a hands off operation. A spring will return the plungerto its most upright
35、position. From this point, the Outflow Meterworks automatically and should not be touched until the test isover. When the lower float switch is activated 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, theOutflow Mete
36、r timer reading and the location of the test shouldbe 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 spacedE2380052tests shall be performed and the arithmetic average of the t
37、esttimes 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 Depth:
38、MTD 5 3.114/OFT 1 0.636 (1)FIG. 1 Outflow MeterE2380053where:MTD = volumetric texture depth defined in TerminologyE 867.9. 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 treat
39、ed in accordancewith Practice E 178 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
40、),10.1.5 Number of 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 read
41、s 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 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 a
42、nd Harmonize Texture and SkidResistance Measurements,” Final report, Permanent International As-sociation of Road Congresses (PIARC), Paris, 1995.(2) Abe, H., Henry, J. J., Tamai, A., and Wambold, J. C., “Measurement ofPavement Macrotexture Using the Circular Texture Meter (CTMeter),”Transportation
43、Research Board Annual Meeting, Washington 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/Runwa
44、y FrictionWorkshop 2003 NASA Wallops 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
45、standard 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
46、 andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committe
47、e, which 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).E2380054
