Effect of Corrosion on the Hysteretic Behavior of Steel Reinforcing Bars and Corroded RC Columns

Abstract

The corrosion of steel reinforcement negatively influences the mechanical performance of reinforced concrete (RC) elements reducing both their strength capacity and ductility. Especially in seismic prone areas, the degradation of the cyclic behavior of corroded RC elements is more intense, limiting the service life of structures and leading to premature failures. In the present paper, in order to study the degraded behavior of the embedded (in concrete) steel reinforcement under cyclic loading, laboratory corrosion experiments were performed on embedded steel reinforcing bars. Thereafter, mechanical tests under dynamic loadings with gradually increased deformations were carried out. From the experimental study, hysteretic models of the non-linear behavior of steel bars were extracted in non-corroded and corroded conditions, in the case of both uniform and pitting corrosion. Based on the hysteretic models of steel bars, an analysis of the cyclic response of (non-corroded and corroded) RC columns was performed using the OpenSees code. The outcomes of the present study indicated the negative consequences of corrosion on the hysteretic behavior of steel reinforcing bars, demonstrating mainly the local reduction in their cross-section (pitting corrosion) combined with the loading history and buckling phenomena as the main factors which deviate the mechanical behavior of steel bars from the classic bilinear model of monotonic loading.