ASTM D4491-1999a(2009) 通过介电常数测试土工合成织物的水渗透性的标准试验方法

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【英文标准名称】:StandardTestMethodsforWaterPermeabilityofGeotextilesbyPermittivity
【原文标准名称】:通过介电常数测试土工合成织物的水渗透性的标准试验方法
【标准号】:ASTMD4491-1999a(2009)
【标准状态】:现行
【国别】:美国
【发布日期】:1999
【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】:D35.03
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:constanthead;fallinghead;geotextiles;permeability;permittivity;Constantheadtesting;Drainagematerials/systems;Fallingheadtest;Flowandflowrate--soil/rock/relatedmaterials;Geosynthetics;Hydraulicconductivity/transmissivity;Liquids-
【摘要】:Thesetestmethodsareconsideredsatisfactoryforacceptancetestingofcommercialshipmentsofgeotextilessincethemethodshavebeenusedextensivelyinthetradeforacceptancetesting.Incaseofadisputearisingfromdifferencesinreportedtestresultswhenusingthesetestmethodsforacceptancetestingofcommercialshipments,thepurchaserandthesuppliershouldconductcomparativeteststodetermineifthereisastatisticalbiasbetweentheirlaboratories.Competentstatisticalassistanceisrecommendedfortheinvestigationofbias.Asaminimum,thetwopartiesshouldtakeagroupoftestspecimensthatareashomogeneousaspossibleandthatarefromalotofmaterialofthetypeinquestion.Thetestspecimensshouldthenberandomlyassignedinnumberstoeachlaboratoryfortesting.TheaverageresultsfromthetwolaboratoriesshouldbecomparedusingStudent''st-testforunpaireddataandanacceptableprobabilitylevelchosenbythetwopartiesbeforethestartoftesting.Ifabiasisfound,eitheritscausemustbefoundandcorrected,orthepurchaserandthesuppliermustagreetointerpretfuturetestresultsinlightoftheknownbias.Permittivityisanindicatorofthequantityofwaterthatcanpassthroughageotextileinanisolatedcondition.Astherearemanyapplicationsandenvironmentalconditionsunderwhichageotextilemaybeused,careshouldbetakenwhenattemptingtoapplytheresultsofthesetestmethodstothefieldperformanceofageotextile.Sincetherearegeotextilesofvariousthicknessesinuse,evaluationintermsoftheirDarcycoefficientofpermeabilitiescanbemisleading.Inmanyinstances,itismoresignificanttoevaluatethequantityofwaterthatwouldpassthroughageotextileunderagivenheadoveraparticularcross-sectionalarea;thisisexpressedaspermittivity.Ifthepermeabilityofanindividualgeotextileisofimportance,anominalcoefficientofpermeability,asrelatedtogeotechnicalengineering,maybecomputed.Bymultiplyingpermittivitytimesthenominalthicknessofthegeotextile,asdeterminedbyTestMethodD5199,thenominalcoefficientofpermeabilityisobtained.Note28212;Thenominalthicknessisusedasitisdifficulttoevaluatethepressureonthegeotextileduringthetest,therebymakingitdifficulttodeterminethethicknessofthefabricunderthesetestconditions.1.1Thesetestmethodscoverproceduresfordeterminingthehydraulicconductivity(waterpermeability)ofgeotextilesintermsofpermittivityunderstandardtestingconditions,intheuncompressedstate.Includedaretwoprocedures:theconstantheadmethodandthefallingheadmethod.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Theinch-poundunitsstatedinparenthesesareprovidedforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:W59
【国际标准分类号】:59_080_70
【页数】:6P.;A4
【正文语种】:英语