Post-Earthquake Fire Resistance and Residual Seismic Capacity of Reinforced Concrete Columns

A series of experiments on 14 square cantilevered columns under constant axial load was conducted to investigate the fire resistance time and residual seismic capacity of reinforced concrete columns subjected to a post-earthquake fire. All specimens were first subjected to a reversed cyclic loading or a simulated earthquake loading, and then exposed to a simulated fire endurance test (wherein high temperature representative of fire loading was imposed on the specimens), or they were subjected to cyclic reversed loading following a post-earthquake fire. The experimental results indicate that the tested specimens satisfied the fire protection requirements of ISO 834 and the Chinese Design Code after moderate earthquake damage, represented in this study by reversed cyclic loading up to a peak drift of 2% and simulated seismic displacement history with a peak drift of 3.5%. Residual drift had a more significant impact than the maximum lateral drift for post-earthquake fire resistance. The seismic response of columns subjected to post-earthquake fire exhibited reduced lateral load capacity, effective stiffness, and ductility. Results from the present study indicate that the lateral drift should be monitored during a fire test, and that lateral drift limits be incorporated into the criteria for post-earthquake fire loading.