Study On The Interface Bond Slip Constitutive Relationship And Influencing Factors Of CFRP-concrete

As a new material,CFRP has been successfully applied to civil engineering industry and achieved some results by researchers duo to the characteristics of light weight, high strength, corrosion resistance.However the interface stripping of CFRP and reinforcement material is common failure forms when considering the failure mode of strengthened structure with CFRP,so the relationship of CFRP reinforcement effect and interface bond properties are closely.Therefore,the interface bond properties of concrete and CFRP has become an important subject in the study of CFRP-concrete structure.In this paper it has been research the interface bond properties of CFRP-concrete under static and fatigue based on the single and double shear of CFRP-concrete structure, which for CFRP and concrete reinforcement structure provide important theoretical and design basis.This article main research content is as follows:(1) By the single shear test of CFRP-concrete different thickness of adhesive.strength of concrete and bond length of FRP is studied,fitting the interface failure energy, the maximum shear stress function relation between force and adhesive shear stiffness and strength of concrete at the same time.(2) From the three important parameters affecting the interfacial bond slip (initial shear stiffness, local maximum interface shear stress, interfacial fracture energy)set out,using the finite element analysis to investigate the influence of three important parameters on the interface bonding performance, and investigate the influence of the bond slip curve on interface bond properties under keeping the three important parameters unchanged.(3) With interfacial fracture energy, modified the CFRP stiffness,considering the influence of effective bond length and width coefficient so that obtaining the bearing capacity calculation formula of correct sexual considering various factors.(4) By the double shear fatigue test of CFRP-concrete, based on the bilinear simplified bond-slip model and the results of fatigue tests,fitting the relationship of interface initial stiffness, residual slip value, bond shear stress with cyclic number N,And then get the constitutive relation of the interface bond slip under different cycles.