A Simplified Reinforcement Model Considering Corrosion and Slip for Seismic Analysis of Reinforced Concrete Columns

A simplified reinforcement model is proposed to consider the effects of both corrosion and reinforcement slip-on seismic performance of reinforced concrete columns. The mechanical properties deterioration of corroded reinforcement are obtained by regression analysis of the available experimental data. Since corrosion may also have a significant influence on bond-slip, a local bond-slip curve with corrosion effect is constructed, by shifting the curve for uncorroded rebar in the slip direction. To fully consider the non-uniformity of bond stress distribution along the development length, a stepped equivalent bond stress is used to simplify the integral calculation of theoretical slip. Subsequently, the cumulative slip and the equivalent strain with slip effect are formulated to modify the parameters of monotonic and hysteretic models of perfectly bonded corroded reinforcement. The response of corroded reinforced concrete columns under cyclic loading is simulated by the fiber section beam element model. Finally, the numerical simulation results and the experimental data are compared. The results show that the ignorance of slip will overestimate the stiffness and bearing capacity of the column by 28.3 and 13.5% respectively, and the yield load, peak load and peak lateral displacement of column decrease with corrosion in longitudinal reinforcement gradually, by 33.8, 16.3 and 56.6% for mass loss percentage 8.0%, respectively. This confirms the ability of the proposed model to simulate the nonlinear seismic response of structures in a corrosive environment.