ASTM D4787-2008 对混凝土底层使用的液体或薄板衬垫的连续验正的标准实施规程

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【英文标准名称】:StandardPracticeforContinuityVerificationofLiquidorSheetLiningsAppliedtoConcreteSubstrates
【原文标准名称】:对混凝土底层使用的液体或薄板衬垫的连续验正的标准实施规程
【标准号】:ASTMD4787-2008
【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】:D01.46
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:conductiveunderlayment;conductivity;discontinuities;highvoltagesparktesters;lowvoltagewetspongetesters;Cracking--coatings;Discontinuities--coatings;Concretepaintapplications;Conductanceandconductivity(electrical);Continuityverificat
【摘要】:Theelectricalconductivityofconcreteisprimarilyinfluencedbythepresenceofmoisture.Otherfactors,whichaffecttheelectricalcontinuityofconcretestructures,includethefollowing:Presenceofmetalrebars,Cementcontentandtype,Aggregatetypes,Admixtures,Porositywithintheconcrete,Aboveorbelowgradeelevation,Indoororoutdoorlocation,Temperatureandhumidity,andAgeofconcrete.Theelectricalconductivityofconcreteitselfmaybesuccessfullyusedforhigh-voltagecontinuitytestingofliningsapplieddirectlywithnospecificconductiveunderlaymentinstalled.However,thevoltagerequiredtofindadiscontinuitymayvarygreatlyfrompointtopointonthestructure.Thisvariancemayreducethetestreliability.Althoughthemostcommonconductiveunderlaymentsareliquidprimersappliedbytrowel,roller,orspray,andwhichcontaincarbonorgraphitefillers,othersmaytaketheformofthefollowing:Sheet-appliedgraphiteveils,Conductivepolymers,Conductivegraphitefibers,Conductivemetallicfibers,andConductivemetallicscreening.Liquid-appliedconductiveunderlaymentsmaybedesirableastheycanservetoaddressimperfectionsintheconcretesurfaceandprovideabetterbaseforwhichtoapplythelining.Thispracticeisintendedforuseonlywithnewliningsappliedtoconcretesubstrates.Inspectingaliningpreviouslyexposedtoanimmersionconditioncouldresultindamagingtheliningorproduceanerroneousdetectionofdiscontinuitiesduetopermeationormoistureabsorptionofthelining.Depositsmayalsobepresentonthesurfacecausingtelegraphing.Theuseofahighvoltagetesteronapreviouslyexposedliningisnotrecommendedbecauseofpossiblesparkthroughwhichwilldamageanotherwisesoundlining.Alowvoltagetestercanbeusedbutcouldproduceerroneousreadings.Theusermayconsiderthispracticewhenperformancerequirementsofthelininginaspecifiedchemicalenvironmentrequireassuranceofaliningfreeofdiscontinuities.Factorsaffectingthedielectricpropertiesandtestvoltageshallbeconsidered.Somefactorsarethecuringtimeofliquid-appliedlinings;thepossiblepresenceofelectricallyconductivefillersorsolvents,orboth;thepossiblepresenceofairinclusionsorvoids;andthecompatibilityofconductiveunderlaymentswiththespecifiedlining.Apulseddchighvoltagemaycausealiningtobreakdownatalowervoltagethanwouldbethecaseforacontinuousdcvoltage.1.1Thispracticecoversproceduresthatmaybeusedtoallowthedetectionofdiscontinuitiesinnonconductiveliningsorothernon-conductivecoatingsappliedtoconcretesubstrates.1.2Discontinuitiesmayincludepinholes,internalvoids,holidays,cracks,andconductiveinclusions.1.3Thispracticedescribesdetectionofdiscontinuitiesutilizingahighvoltagesparktesterusingeitherpulsedorcontinuousdcvoltage.Note18212;ForfurtherinformationondiscontinuitytestingrefertoNACEStandardRP0188-88orPracticeD5162.1.4Thispracticedescribesproceduresbothwithandwithouttheuseofaconductiveunderlayment.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesareforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsi......
【中国标准分类号】:Q13
【国际标准分类号】:91_100_30
【页数】:4P.;A4
【正文语种】:英语