【英文标准名称】:StandardTestMethodforMeasuringtheCoefficientofRetroreflectedLuminanceofPavementMarkingsinaStandardConditionofContinuousWetting(RL-Rain)
【原文标准名称】:连续浸润标准条件下路面标记反射亮度系数测量的标准试验方法
【标准号】:ASTME2176-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E12.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:continuouswetting;dryretroreflection;pavementmarkings;portableretroreflectometer;wetretroreflection;Geometricanalysis--paints/relatedcoatings/materials;Dryretroreflection;Mobileretroreflectometers;Pavementmarkingmaterials;Portableretr
【摘要】:Thecoefficientofretroreflectedluminance,RL,isthepropertyofapavementmarkingsystemthatprovidesameasureoftheretroreflectiveefficiencyofthemarkinganddependsonfactorssuchasthematerialsused,age,andwearpattern.Theseconditionsshallbeobservedandnotedbytheuser.Underidenticalconditionsofheadlightilluminationanddriver''sviewing,largervaluesofRLcorrespondtohigherlevelsofvisibilityatcorrespondinggeometry.Thepavementmarking''smeasuredretroreflectiveefficiencyinconditionsofcontinuouswettingmaybeusedtocharacterizethepropertiesofthemarkingontheroadaswateriscontinuouslyfallingonit.Theretroreflectiveefficiencyofthemarkinginconditionsofcontinuouswettingmaybedifferentthanindry,wetordampconditions.ThistestmethodmayproducemeasurementsofRL-Rainforpavementmarkingsystemsthatdonotcorrelatetonighttimevisibilitydistanceduringtypicalrainevents.Therainfallintensitysimulatedbythistestmethodissignificantlygreaterthanmostordinaryorevenheavyrainfallevents.Asaresult,thetestspecimen,unlessithasverticalfeaturesexceeding3mm,becomesflooded.Opticswithanindexofrefractionlessthan2.0arepracticallyineffectivewhenimmersedinwater.Thus,thetestmethodisoflimitedapplicabilityforassessingthewetretroreflectivepropertiesofpavementmarkingsystemshavingverticalfeatureslessthan3mmoropticshavinganindexofrefractionlessthan2.0.Retroreflectivityofpavement(road)markingsdegradeswithtrafficwearandrequiresperiodicmeasurementtoensurethatsufficientlinevisibilityisprovidedtodrivers.Newlyinstalledpavementmarkingsmayhaveanaturalsurfacetensionorreleaseagentswhichpreventwettingofthemarkingbyrain/water.Thisphenomenonproducesunreliableandunrepeatableresultswhenmeasuringretroreflectiveefficiencyunderwetconditions.Thisnon-wettingphenomenonisgenerallyeliminatedafteronemonthofwearandweatheringontheroad.AwettingagentcanbeusedtoestimatetheRL-Rainpropertiesofnewmarkings(see5.4).Roadwaycharacteristicssuchaslongitudinalslope,crossslopeandpavementporositywillimpacttheresultsofthistestmethod.1.1Thistestmethodcoversameasurementofthewetretroreflective(RL-Rain)propertiesofhorizontalpavementmarkingmaterials,suchastrafficstripesandroadsurfacesymbols.1.2Thismethodofmeasuringwetretroreflectiveproperties(RL)ofpavementmarkingsutilizesamethodofcontinuouslywettingthemarkingduringmeasurement(seeFig.1).Note18212;TestMethodE2177maybeusedtodescribetheretroreflectivepropertiesofpavementmarkingsinconditionsofwetnessafteraperiodofrain.1.3Thistestmethodismostsuitableforlaboratoryuseundercontrolledconditions,butmayalsobeusedforfieldmeasurementswhenthenecessarycontrolsandprecautionsarefollowed.1.4ThistestmethodspecifiestheuseofreflectometersthatcanmeasurepavementmarkingsperTestMethodE1710.Theentranceandobservationanglesrequiredoftheretroreflectometerinthistestmethodarecommonlyreferredtoasx201C;30metergeometry.x201D;1.5Thistestmethodhasbeenshowntoproducereasonableresultsforpavementmarkingsystemswithopticshavinganindexofrefractiongreaterthan2.0andstructuredmarkingshavingverticalstructuresgreaterthanorequalto3mm.U......
【中国标准分类号】:Q85
【国际标准分类号】:93_080_20
【页数】:6P.;A4
【正文语种】:英语