Study On The Bond-slip Constitutive Relation Between Corroded Steel Bar And Concrete Under The Coupling Action Of Load And Environment

The basic precondition for conjunct work of the rebar and the concrete in reinforced concrete structures is bonding action.After the rebar is seriously rusted,The bonding performance between rebar and concrete will significantly degrade,and the durability of the structure and security will severely affected.Research on the bonding performance between rebar and concrete is important in both theory and practice.In terms of the current research results,most researchers only consider the influence of the environment or the corrosion degree on specimen.However,the rebar is gradually rusted under certain load cases.This paper will take advantage of reinforced concrete bolck drawing test under the coupling action of the loading and the environment,research on the bonding performance between rusted rebar and concrete,fit out the bond-slip constitutive relation of reinforced concrete,establish a reinforced concrete bond damage model based on damage theory,and according to the fitted constitutive relation,establish a finite element numerical model of reinforced concrete drawing test.In this paper,main works are as follows :(1)By analyzing the academic scholars’ research on bonding performance of reinforced concrete,we compare various scholars’ calculation formula of bond-slip performance of reinforced concrete,expound the advantages and disadvantages of the previous studies,inductive which aspect needs to strengthen and discussion.(2)By arranging loading and rusting method of drawing block,we analyze damage form and the bond-slip relationship of reinforced concrete block under the condition of different loading sectors and different rusting rate,and the influence law of bonding performance.Then,combine the test date with it,we fit out the bond-slip constitutive relation of reinforced concrete under the coupling action of the loading and the environment.(3)By setting a damage variable,we establish a developing equation of reinforced concrete bond damage,establish a bond damage model of reinforced concrete under the coupling action of the loading and the environment;according to the fitted bond-slip constitutive relationship and take advantage of ABAQUS software analysis method,we analyze drawing blocks under the condition of different loading sectors and different rusting rate,through comparing with the test results,verify the correctness of the fitted constitutive relation.