ASTM D5335-2008 用粘结的电阻应变仪测定岩石热膨胀线性系数的标准试验方法

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【英文标准名称】:StandardTestMethodforLinearCoefficientofThermalExpansionofRockUsingBondedElectricResistanceStrainGauges
【原文标准名称】:用粘结的电阻应变仪测定岩石热膨胀线性系数的标准试验方法
【标准号】:ASTMD5335-2008
【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】:D18.12
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:heatingtests;straingauges;temperature;thermalexpansion;thermalproperties;Electricresistancestraingages;Heatingtests--soil/rock;Linearthermalexpansion--rock;Straingages;Straintesting--soil/rock/relatedmaterials/applications;Temperatu
【摘要】:Informationconcerningthethermalexpansioncharacteristicsofrocksisimportantinthedesignofanyundergroundexcavationwherethetemperatureofthesurroundingrockmaybealtered.Thermalstraincausesthermalstressthatultimatelyaffectsthestabilityofundergroundexcavations.Examplesofapplicationswhererockthermalstrainisimportantinclude:nuclearwasterepositories,undergroundpowerstations,compressedairenergystoragefacilities,andgeothermalenergyfacilities.Thelinearcoefficientofthermalexpansion,x03B1;,ofrockisknowntovaryasthetemperaturechanges.Rockthermalstrainisnormallynotalinearfunctionoftemperature.Thistestmethodprovidesaprocedureforcontinuouslymonitoringthermalstrainasafunctionoftemperature.Therefore,informationonhowachangeswithtemperatureisobtained.Othermethodsofmeasuringtheexpansioncoefficientofrockbyaveragingthethermalstrainofalargespecimenoveratemperaturerangeofmanydegreesmayresultinfailuretodeterminethevariationinx03B1;ofthatrockforoneormoreofthefollowingreasons:Alphaisnotalwayslinearwithtemperature,Somerocksareanisotropichavingdirectionalcharacteristicswhichcanvarybymorethanafactoroftwo.Alphamayhaveanegativevalueinonedirectionand,atthesametime,apositivevalueintheothers.Straingauges,bothwireandfoiltypes,havebeensuccessfullyemployedtomeasurethethermalexpansioncoefficientsofrock.Thesecoefficientsarefrequentlyverysmall,beingontheorderofmillionthsofamillimetrepermillimetreforeachdegreeCelsius(millionthsofaninchperinchforeachdegreeFahrenheit).Thethermalstrainofrocksisaboutonetenththatofplasticsandonehalforonequarterthatofmanymetals.Therefore,measurementmethodsforrocksrequiregreaterprecisionthanmethodsthatareroutinelyusedonplasticsandmetals.Note48212;Notwithstandingthestatementsonprecisionandbiascontainedinthistestmethod;theprecisionofthistestmethodisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting.UsersofthistestmethodarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliabletesting.Reliabletestingdependsonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thistestmethodcoversthelaboratorydeterminationofthelinear(one-dimensional)coefficientofthermalexpansionofrockusingbondedelectricresistancestraingauges.1.2Thistestmethodisapplicableforunconfinedpressureconditionsoverthetemperaturerangefrom20to260x00B0;C(68to500x00B0;F).Note18212;Unconfinedtestsperformedatelevatedtemperaturesmayalterthemineralogyorgrainstructureofthetestspecimen.Thisalterationmaychangethephysicalandthermalpropertiesofthetestspecimen.Note28212;Thestraingaugesaremountedwithepoxy.Mostcommerciallyavailablehightemperatureepoxiesrequireelevatedtemperaturecuring.Theelevatedtemperaturerequiredforthiscuringmayalterthephysicalandthermalpropertiesofthetestspecimen.Epoxyshouldbeselectedbaseduponthemaximumexpectedtesttemperature.Roomtemperaturecuringepoxyshouldbeusedwheneverpossible.1.3Thetestspecimensmaybeeithersaturatedordr......
【中国标准分类号】:P13
【国际标准分类号】:93_020
【页数】:5P.;A4
【正文语种】:英语