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【英文标准名称】:Opticalfibres-Part2-30:productspecifications-SectionalspecificationforcategoryA3multimodefibres.
【原文标准名称】:光学纤维.第2-30部分:产品规范.A3类多模光纤分规范.
【标准号】:NFC93-841-2-30-2009
【标准状态】:现行
【国别】:法国
【发布日期】:2009-09-01
【实施或试行日期】:2009-09-19
【发布单位】:法国标准化协会(FR-AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:Design;Dimensions;Electricalengineering;Fibreoptics;Generalsection;Multimodefibres;Opticalwaveguides;Optoelectronics;Sectionalspecification;Specification
【摘要】:
【中国标准分类号】:M33
【国际标准分类号】:33_180_10
【页数】:22P;A4
【正文语种】:其他


【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