Anchorage slip effect in RC structures

Abstract

A numerical model that can simulate the cracking behaviour of a reinforced concrete (RC) structure subjected to monotonic loading is introduced. A criterion to take into account the biaxial behaviour of concrete is designed on the basis of Kupfer's experimental results, and the equivalent uniaxial stress–strain relationship with a tension-stiffening effect is used for an effective simulation of the inelastic behaviour induced from the cracking of concrete. Moreover, an improved numerical model to implement the bond-slip effect in RC structures, in which the consideration of the bond-slip effect is virtually impossible in the numerical analysis as the reinforcing steels are uniformly distributed through the entire domain, is developed in this paper. Instead of using the bond-link elements that connect the concrete and steel nodes with the spring elements, a relationship between the steel stress and the end-slip obtained from an idealised pull-out specimen is implemented at the end face of RC structures. The use of these boundary spring elements makes it possible to simulate precisely the cracking behaviour of the RC structures affected most by the bond-slip. Finally, correlation studies between the numerical results and the experimental results are conducted in order to verify the soundness of the introduced boundary spring element model.