A new numerical model of the corroded steel–concrete interface

The main cause of deterioration of reinforced concrete structures is corrosion of reinforcing steel. It causes cracking and eventually spalling of the concrete cover, reduction of cross-sectional area of reinforcing steel and damage to the bond between concrete and reinforcement. The present paper concentrates on investigation of the effect of corrosion on the interface between reinforcing steel and concrete. It starts with a brief overview of existing experimental data as well as analytical and numerical models considering the corrosion-induced deterioration of the steel–concrete interface. A new model of the corroded steel–concrete interface is then developed based on available experimental data. The model takes into account two bond mechanisms, namely adhesion and friction, and includes the influence of corrosion. The interfacial model is calibrated using experimental data from pull-out tests and then implemented in an axisymmetric formulation into a finite-element numerical model. Concrete modelling includes the effect of drying shrinkage. The thermal analogy method is implemented for simulations of corrosion and drying shrinkage. Finally, the finite-element model is used to simulate pull-out tests of corroded plain round bars. Results of the finite-element simulations are presented and compared with test results.