Influence of concrete strength and diameter of reinforcing bar onpullout tests using finite element analysis

Abstract

The numerical investigations have been carried out on simulating bond-slip behaviour between concrete and steel reinforcing bar using ABAQUS explicit finite element code. The major contribution of this paper is to study the influence of varying concrete strength and diameter of reinforcing bar on bond slip behaviour. The inelastic behaviour of concrete and steel reinforcing bar were defined using concrete damaged plasticity model and Johnson-Cook model respectively which is available in ABAQUS/CAE. A spring-translator element available in ABAQUS, was used to simulate the bond slip phenomena in reinforced concrete during pull-out. The results thus predicted through simulations were compared with the experimental results available in literature. It was observed that the translator used in the present study simulates the bond behaviour efficiently. It was also observed that the predicted and measured deformed profile was found in good agreement. Further, the simulations were conducted on principal parameters to study the influence of concrete compressive strength and the bar diameter. In case of 40MPa concrete the bond stress improved by 60% when 16 mm diameter bars were replaced by 20 mm diameter bars. Increasing the bar diameter is an efficient method to improve the bond strength characteristics. However, the improvement in bond stress was found to be insignificant when concrete strength was increased from 60 MPa to 100 MPa.