Designation:C1550−12aStandardTestMethodforFlexuralToughnessofFiberReinforcedConcrete(UsingCentrallyLoadedRoundPanel)1ThisstandardisissuedunderthefixeddesignationC1550;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofflexuraltoughnessoffiber-reinforcedconcreteexpressedasenergyabsorptioninthepost-crackrangeusingaroundpanelsup-portedonthreesymmetricallyarrangedpivotsandsubjectedtoacentralpointload.Theperformanceofspecimenstestedbythismethodisquantifiedintermsoftheenergyabsorbedbetweentheonsetofloadingandselectedvaluesofcentraldeflection.1.2Thistestmethodprovidesforthescalingofresultswheneverspecimensdonotcomplywiththetargetthicknessanddiameter,aslongasdimensionsdonotfalloutsideofgivenlimits.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C31/C31MPracticeforMakingandCuringConcreteTestSpecimensintheFieldC125TerminologyRelatingtoConcreteandConcreteAg-gregatesC670PracticeforPreparingPrecisionandBiasStatementsforTestMethodsforConstructionMaterials3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthistestmethod,refertoTerminologyC125.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1centraldeflection—thenetdeflectionatthecenterofthepanelmeasuredrelativetoaplanedefinedbythethreepivotsusedtosupportthepanel;thisisaconditioneddeflectionthatexcludesextraneousdeformationsoftheloadtrainandlocalcrushingofthepanelatthepointofloadapplicationandpointsofsupport.3.2.2compliance—ameasureoftheten...
