【英文标准名称】:StandardTestMethodforFlexuralToughnessofFiberReinforcedConcrete(UsingCentrallyLoadedRoundPanel)
【原文标准名称】:纤维增强混凝土的挠性强度的标准试验方法(利用中心负荷圆形板)
【标准号】:ASTMC1550-2010a
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【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】:C09.42
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:energyabsorption;fiber-reinforcedconcrete;flexure;post-crackbehavior;toughness;Concrete;Fiber-reinforcedconcrete;Flexuraltesting--concrete;Postcrackingstrength
【摘要】:Thepost-crackbehaviorofplate-like,fiber-reinforcedconcretestructuralmembersiswellrepresentedbyacentrallyloadedroundpaneltestspecimenthatissimplysupportedonthreepivotssymmetricallyarrangedarounditscircumference.Suchatestpanelexperiencesbi-axialbendinginresponsetoacentralpointloadandexhibitsamodeoffailurerelatedtotheinsitubehaviorofstructures.Thepost-crackperformanceofroundpanelssubjecttoacentralpointloadcanberepresentedbytheenergyabsorbedbythepaneluptoaspecifiedcentraldeflection.Inthistestmethod,theenergyabsorbeduptoaspecifiedcentraldeflectionistakentorepresenttheabilityofafiber-reinforcedconcretetoredistributestressfollowingcracking.Note18212;Theuseofthreepivotedpointsupportsinthetestconfigurationresultsindeterminateout-of-planereactionspriortocracking,howeverthesupportreactionsareindeterminateaftercrackingduetotheunknowndistributionofflexuralresistancealongeachcrack.Thereisalsoachangeintheloadresistancemechanisminthespecimenasthetestproceeds,startingwithpredominantlyflexuralresistanceandprogressingtotensilemembraneactionaroundthecenterastheimposeddeflectionisincreased.Theenergyabsorbeduptoaspecifiedcentraldeflectionisrelatedtothetoughnessofthematerialbutisspecifictothisspecimenconfigurationbecauseitisalsodeterminedbythesupportconditionsandsizeofthespecimen.Selectionofthemostappropriatecentraldeflectiontospecifydependsontheintendedapplicationforthematerial.Theenergyabsorbedupto5mmcentraldeflectionisapplicabletosituationsinwhichthematerialisrequiredtoholdcrackstightlyclosedatlowlevelsofdeformation.Examplesincludefinalliningsinundergroundcivilstructuressuchasrailwaytunnelsthatmayberequiredtoremainwater-tight.Theenergyabsorbedupto40mmismoreapplicabletosituationsinthatthematerialisexpectedtosufferseveredeformationinsitu(forexample,shotcreteliningsinminetunnelsandtemporaryliningsinswellingground).Energyabsorptionuptointermediatevaluesofcentraldeflectioncanbespecifiedinsituationsrequiringperformanceatintermediatelevelsofdeformation.Themotivationforuseofaroundpanelwiththreesupportsisbasedonthewithin-batchrepeatabilityfoundinlaboratoryandfieldexperience.Theconsistencyofthefailuremodethatarisesthroughtheuseofthreesymmetricallyarrangedsupportpivotsresultsinlowwithin-batchvariabilityintheenergyabsorbedbyasetofpanelsuptoaspecifiedcentraldeflection.Theuseofroundpanelsalsoeliminatesthesawingthatisrequiredtoprepareshotcretebeamspecimens.Thenominaldimensionsofthepanelare75mminthicknessand800mmindiameter.Thicknesshasbeenshowntostronglyinfluencepanelperformanceinthistest,whilevariationsindiameterhavebeenshowntoexertaminorinfluenceonperformance.Correctionfactorsareprovidedtoaccountforactualmeasureddimensions.Note28212;Thetargetdimensionsofthepanelspecimenusedinthistestareheldconstantregardlessofthecharacteristicsofaggregateandfibersusedintheconcretecomprisingthespecimen.Post-crackperformancemaybeinfluencedbysizeandboundaryeffectsiflargeaggregateparticlesorlongfibersareusedintheconcrete.Theseinfluencesareacknowledgedandacceptedinthistestmethodbecauseissuesofsizeeffectandfiberalignmentariseinactualstructuresandnosingletestspecimencansuitablymodelstructuresofallsizes.Differencesinpost-crackbehaviorexhibitedinthistestmethodcanbeexpectedrelativetocastfiber-reinforced........
【中国标准分类号】:Q23
【国际标准分类号】:91_100_40
【页数】:14P.;A4
【正文语种】:英语