Deterioration Model for Corroded Circular Columns

A hysteretic model is essential for the study of the seismic performance of structures. Due to the ability to capture the component strength and stiffness deterioration, the modified Ibarra–Medina–Krawinkler (ModIMK) hysteretic model has been widely used recently. Previous studies on the ModIMK model have mainly focused on reinforced-concrete (RC) square columns, and very few have focused on circular columns. In contrast, studies on the ModIMK model specifically for corroded circular RC columns have not yet been conducted. For this reason, a database of 35 corroded and uncorroded comparison columns was gathered, and the hysteretic model parameters of each column were calibrated. The ratios of the model parameters of the corroded and uncorroded comparison components are defined as the corrosion-induced deterioration coefficients (CIDCs). After the CIDCs were calculated for all the corroded columns, the empirical equations for the CIDCs were established using regression methods. Through determining the ModIMK model parameters of the corroded columns when they were uncorroded, combined with these equations, the ModIMK model parameters of the corroded circular columns were calculated and their hysteretic models defined. Finally, the accuracy of the ModIMK model’s prediction method was demonstrated using the hysteretic response analyses of four components in the database and the application of two components outside the database. The prediction method lays the foundation for applying the ModIMK model to structures containing corroded circular RC columns.