BFRP筋和钢筋混合配筋混凝土梁抗弯承载力计算方法.docx

BFRP筋和钢筋混合配筋混凝土梁抗弯承载力计算方法
BFRP筋和钢筋混合配筋混凝土梁抗弯承载力计算方法
Abstract
TheuseofBasaltFiberReinforcedPolymer(BFRP)asanalternativereinforcementmaterialinreinforcedconcretebeamshasrecentlygainedmuchattentionduetoitshighstrengthandcorrosionresistanceproperties.ThispaperdiscussesthecalculationmethodfortheflexuralcapacityofBFRPandsteelreinforcedconcretebeams.ThedesignmethodisbasedonamodifiedWhitneystrengthreductionfactorandthebi-linearstress-strainrelationshipofBFRP.
Introduction
Inrecentyears,theuseofBFRPasanalternativereinforcementmaterialinreinforcedconcretestructureshasbecomemoreprevalent.OneofthereasonsforthisshiftisthegoodmechanicalpropertiesofBFRP.BFRPhasahightensilestrength,modulusofelasticity,andfatigueresistance.BFRPalsohasadvantagesoverotherreinforcementmaterialsintermsofenvironmentalsustainabilityduetoitsrenewablenature.However,theuseofBFRPreinforcementinconcreteelementsrequiresthedevelopmentofdesignmethodsandcodestoensurethesafeandefficientuseofthismaterial.
TheuseofBFRPasareinforcementmaterialinconcretestructuresposeschallengesintermsofcompatibilitywithconcreteandsteelreinforcements,whicharethetwocommonreinforcementmaterialsusedinreinforcedconcretestructures.ThischallengecanbeovercomebycombiningBFRPwithsteelreinforcementsindifferentproportionstoproducehybridreinforcedconcrete.
Designmethodology
Theprimaryobjectiveofthedesignmethodologyistodeterminethemaximumallowableflexuralcapacityofthehybridreinforcedconcretebeam.ThemethodisbasedonamodifiedWhitneystrengthreductionfactor(ϕ)thatconsiderstheeffectofBFRPandsteelreinforcementontheultimatestrengthofthebeam.ThemodifiedWhitneystrengthreductionfactor(ϕm)isgivenbythefollowingequation:
ϕm=ϕc+ϕBFRP+ϕsteel
Where;
ϕc=strengthreductionfactorforconcrete=0.65
ϕBFRP=strengthreductionfactorforBFRPreinforcement=0.90
ϕsteel=strengthreductionfactorforsteelreinforcement=0.85
Themaximumflexuralcapacityofthehybridreinforcedconcretebeamiscalculatedasfollows:
Mn=ϕm×M
Where;
Mn=maximumflexuralcapacityofthehybridreinforcedconcretebeam
M=momentc