Structural assessment of the coupled influence of corrosion damage and seismic force on the cyclic behaviour of RC columns

Abstract

Steel bar corrosion, which is considered to be a significant degradation issue in reinforced concrete (RC) structures, may cause premature failure during seismic events. Many experimental studies have been conducted to investigate the coupled effect of steel bar corrosion and seismic force on the structural behaviour of RC columns. However, modelling of the structural response of corroded RC columns has received comparatively less attention. An accurate assessment of the structural response of corrosion-damaged RC columns may extend the life span and reduce maintenance costs. In this study, we applied the finite element method and developed a numerical model to simulate the seismic performance of corroded RC columns. The numerical model was developed to account for corrosion-induced cracking and bond deterioration between steel and concrete depending on the spatial variation of steel bar corrosion. The finite element (FE) model was validated using the results obtained from three different sets of experimental tests available in the literature with an average corrosion ratio ranging from initial to severe levels. The results obtained using the proposed numerical model demonstrated an excellent correlation with all the experimental results, thereby making it suitable for investigating the seismic behaviour of corrosion-damaged RC columns in terms of stiffness, strength, displacement capacity, and cracking pattern. After validation, the numerical model was used to investigate the effect of localised and uneven distribution of corrosion on the cyclic response of RC columns.