标准资料网-标准资料免费资源平台

【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


【英文标准名称】:Earth-movingmachinery-Safety-Part4:Requirementsforbackhoe-loaders
【原文标准名称】:土方机械.安全性.第4部分:反铲挖土机-装载机用要求
【标准号】:ISO20474-4-2008
【标准状态】:现行
【国别】:国际
【发布日期】:2008-12
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC127
【标准类型】:()
【标准水平】:()
【中文主题词】:事故预防;附加硬件设备;建筑机械;联合挖泥机-装载机;定义;定义(术语);拖铲挖土机;土方机械;挖掘机;装料机;装载机;职业安全;保护措施;安全性;安全措施;机械安全性;安全性要求;规范(验收);挖沟机;工作场所安全性
【英文主题词】:Accidentprevention;Add-onpiece;Buildingmachines;Combineddredger-loaders;Definition;Definitions;Dragshovels;Earth-movingequipment;Excavators;Loaders;Occupationalsafety;Protectivemeasures;Safety;Safetymeasures;Safetyofmachinery;Safetyrequirements;Specification(approval);Trenchexcavators;Workplacesafety
【摘要】:ThispartofISO20474givesthesafetyrequirementsspecifictowheeledandcrawlerbackhoeloadersasdefinedinISO6165.ItisintendedtobeusedinconjunctionwithISO20474-1,whichspecifiesgeneralsafetyrequirementscommontoearth-movingmachinefamilies,andwithISO/TS20474-14,whichgivesinformationonprovisionsthataremandatoryinparticularcountriesorregions.ThespecificrequirementsgiveninthispartofISO20474takeprecedenceoverthegeneralrequirementsofISO20474-1.ThispartofISO20474dealswithallsignificanthazards,hazardoussituationsandeventsrelevanttotheearth-movingmachinerywithinitsScopewhenusedasintendedorunderconditionsofmisusereasonablyforeseeablebythemanufacturer(seealsoISO/TS20474-14).Itspecifiestheappropriatetechnicalmeasuresforeliminatingorreducingrisksarisingfromsignificanthazards,hazardoussituationsoreventsduringcommissioning,operationandmaintenance.Itisnotapplicabletomachinesmanufacturedbeforethedateofitspublication.
【中国标准分类号】:P97
【国际标准分类号】:53_100
【页数】:14P;A4
【正文语种】:英语