Impact of Reinforcement Corrosion on the Seismic Performance of Existing RC Buildings

The degradation of reinforced concrete (RC) structures due to corrosion is one of the most critical issues affecting their safety, durability, and seismic performance. Environmental agents such as carbon dioxide and chlorides penetrate the concrete matrix, triggering corrosion of the embedded steel reinforcement and leading to significant changes in the mechanical properties of both concrete and steel. These processes reduce strength, ductility, and bond capacity, compromise confinement, and ultimately diminish the load-bearing capacity of structural elements. This study investigates the mechanisms of corrosion and their effects on the structural performance of RC buildings, presenting analytical models capable of incorporating degradation phenomena into the assessment of existing structures. The research includes a detailed analysis of the electrochemical processes leading to corrosion, the resulting material property variations, and the structural implications. A nonlinear static (pushover) analysis is then performed on a representative case study structure to evaluate how uniform corrosion influences seismic response parameters such as capacity curves, displacement ductility, shear strength, and safety indices. The results highlight a significant reduction in seismic performance, emphasizing the importance of accounting for degradation effects in vulnerability assessments and retrofitting strategies. The proposed modeling approach provides a more realistic prediction of structural behaviour over time and supports engineers in making informed decisions regarding maintenance, repair, and seismic upgrading of aging RC infrastructure.