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【英文标准名称】:StandardTestMethodforMeasuringtheCoefficientofRetroreflectedLuminance(RL)ofPavementMarkingsinaStandardConditionofWetness
【原文标准名称】:标准潮湿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】:ASTME2177-2001(2009)
【标准状态】:现行
【国别】:美国
【发布日期】:2001
【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】:dryretroreflection;mobileretroreflectometers;pavementmarkings;portableretroreflectometer;retroreflectioninwetconditions;Dryretroreflection;Mobileretroreflectometers;Pavementmarkingmaterials;Portableretroreflectometers;Retroreflectedl
【摘要】:Thenighttimeperformanceofpavementmarkingsisdeterminedbythecoefficientofretroreflectedluminance,RL,beitdryorwet,anddependsonthematerialsused,age,andwearpattern.Theseconditionsshallbeobservedandnotedbytheuser.Underthesameconditionsofheadlightilluminationanddriver''sviewing,largervaluesofRLcorrespondtohigherlevelsofvisualperformanceatcorrespondinggeometry.Thepavementmarking''smeasuredperformanceinthestandardconditionofwetnessisusedtocharacterizetheperformanceofthemarkingontheroadwhenwet.Newlyinstalledpavementmarkingsmayhaveanaturalsurfacetensionorreleaseagentsthatpreventwettingoftheproductbywater.Thewaterwilltendtox201C;beadupx201D;onthemarking.Thisx201C;nonwettingx201D;conditionisusuallyshortlived.Pavementmarkingsthathavebeenontheroadforonemonthpriortotestingusuallydonotexhibitthisnon-wettingphenomenon.(Warningx2013;Thisphenomenonproducesaninterferencewhenassessingthewetcharacteristicsofapavementmarking.Attemptstomeasuremarkingswiththissurfacex201C;non-wettingx201D;orx201C;beadingx201D;ofthewatermaygivehighervalues.)Theretroreflectivity,RL,ofpavement(road)markingsdegradeswithtrafficwearandrequiresperiodicmeasurementtoensurethatsufficientlinevisibilityisprovidedtodrivers.ForexampleseeSpecificationD6359fordryretroreflectivityrequirements.Foragivenviewingdistance,measurementsofRLmadewitharetroreflectometerhavingageometrycorrespondingtothatviewingdistanceareagoodindicatorofthevisualrankingofthematerialmeasured.AsspecifiedbyTestMethodE1710,themeasurementgeometryoftheinstrumentisbasedonaviewingdistanceof30m,aneyeheightof1.2mandaheadlightmountingheightof0.65m(seeAppendixX1).Itshallbetheresponsibilityoftheusertoemployaninstrumenthavingthespecifiedobservationandentranceangles.1.1Thistestmethodcoversthemeasurementofthewetretroreflective(RL)propertiesofhorizontalpavementmarkingmaterials,suchastrafficstripesandroadsurfacesymbols,usingaportableormobileretroreflectometerthatcanbeplacedonorbeforetheroadmarkingtomeasuretheretroreflectionattheprescribedgeometry.1.2Thismethodofmeasuringthewetretroreflectiveproperties(RL)ofpavementmarkingsmeasuresthewetretroreflectivityinastandardconditionofwetness(seeFig.1).1.2.1Discussion151;Thistestconditiontypicallyexists(1)afterarainfallhasendedandthepavementmarkingsarestillwetor(2)asthemarkingsarewetfromdeworhumidity.1.3Retroreflectiveperformanceobtainedwiththistestinconditionsofwetnessdoesnotnecessarilyrelatetohowmarkingsperforminconditionsofrain,thatis,asmarkingsarebeingrainedupon.Note18212;TestMethod