标准名称：	汽车起重机和轮胎起重机用平衡阀
中标分类：	机械 >> 通用机械与设备 >> 起重机械
替代情况：	转化为JB/T 9739.1-99
发布日期：
实施日期：	1991-01-01
首发日期：
作废日期：
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【英文标准名称】:StandardTestMethodforFlexuralPerformanceofFiber-ReinforcedConcrete(UsingBeamWithThird-PointLoading)
【原文标准名称】:纤维增强混凝土的弯曲性能的标准试验方法(使用三点负荷简支梁)
【标准号】:ASTMC1609/C1609M-2010
【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】:fiber-reinforcedconcrete;first-peakstrength;flexuraltoughness;peakstrength;residualload;residualstrength;Beamtest;Concrete;Concrete(fiber-reinforced);Flexuraltesting
【摘要】:Thefirst-peakstrengthcharacterizestheflexuralbehaviorofthefiber-reinforcedconcreteuptotheonsetofcracking,whileresidualstrengthsatspecifieddeflectionscharacterizetheresidualcapacityaftercracking.Specimentoughnessisameasureoftheenergyabsorptioncapacityofthetestspecimen.Theappropriatenessofeachparameterdependsonthenatureoftheproposedapplicationandthelevelofacceptablecrackinganddeflectionserviceability.Fiber-reinforcedconcreteisinfluencedindifferentwaysbytheamountandtypeoffibersintheconcrete.Insomecases,fibersmayincreasetheresidualloadandtoughnesscapacityatspecifieddeflectionswhileproducingafirst-peakstrengthequaltooronlyslightlygreaterthantheflexuralstrengthoftheconcretewithoutfibers.Inothercases,fibersmaysignificantlyincreasethefirst-peakandpeakstrengthswhileaffectingarelativelysmallincreaseinresidualloadcapacityandspecimentoughnessatspecifieddeflections.Thefirst-peakstrength,peakstrength,andresidualstrengthsdeterminedbythistestmethodreflectthebehavioroffiber-reinforcedconcreteunderstaticflexuralloading.Theabsolutevaluesofenergyabsorptionobtainedinthistestareoflittledirectrelevancetotheperformanceoffiber-reinforcedconcretestructuressincetheydependdirectlyonthesizeandshapeofthespecimenandtheloadingarrangement.Theresultsofthistestmethodmaybeusedforcomparingtheperformanceofvariousfiber-reinforcedconcretemixturesorinresearchanddevelopmentwork.Theymayalsobeusedtomonitorconcretequality,toverifycompliancewithconstructionspecifications,obtainflexuralstrengthdataonfiber-reinforcedconcretememberssubjecttopurebending,ortoevaluatethequalityofconcreteinservice.Theresultsofthisstandardtestmethodaredependentonthesizeofthespecimen.Note58212;Theresultsobtainedusingonesizemoldedspecimenmaynotcorrespondtotheperformanceoflargerorsmallermoldedspecimens,concreteinlargestructuralunits,orspecimenssawnfromsuchunits.Thisdifferencemayoccurbecausethedegreeofpreferentialfiberalignmentbecomesmorepronouncedinmoldedspecimenscontainingfibersthatarerelativelylongcomparedwiththecross-sectionaldimensionsofthemold.Moreover,structuralmembersofsignificantlydifferentthicknessexperiencedifferentmaximumcrackwidthsforagivenmid-spandeflectionwiththeresultthatfibersundergodifferentdegreesofpull-outandextension.1.1Thistestmethodevaluatestheflexuralperformanceoffiber-reinforcedconcreteusingparametersderivedfromtheload-deflectioncurveobtainedbytestingasimplysupportedbeamunderthird-pointloadingusingaclosed-loop,servo-controlledtestingsystem.1.2Thistestmethodprovidesforthedeterminationoffirst-peakandpeakloadsandthecorrespondingstressescalculatedbyinsertingthemintheformulaformodulusofrupturegiveninEq1.Italsorequiresdeterminationofresidualloadsatspecifieddeflections,thecorrespondingresidualstrengthscalculatedbyinsertingthemintheformulaformodulusofrupturegiveninEq1(seeNote1).Itprovidesfordeterminationofspecimentoughnessbasedontheareaundertheload-deflectioncurveuptoaprescribeddeflection(seeNote2)andthecorrespondingequivalentflexuralstrengthratio.Note18212;Residualstrengthisnotatruestressbutanengineeringstresscomputedusingsimpleengineeringbendingtheoryforlinearelasticmaterialsandgross(uncracked)sectionproperties.Note28212;Specimentoughnessexpressedintermsoftheareaundertheload-deflectioncurveisan......
【中国标准分类号】:Q23
【国际标准分类号】:91_100_40
【页数】:9P.;A4
【正文语种】:英语