Investigation of the Static Pushover Capacity Curves of a Reinforced Concrete Structural System Exposed to High Temperatures

In this study, seismic performance of reinforced concrete (RC) structural systems exposed to high temperature were investigated. Aiming at this goal, a RC structure with 4 floors and 4 spacings was considered. Primarily, column and beam elements were modeled by using ANSYS software and then, in order to obtain the temperature distributions in cross-sections of the reinforced concrete elements, thermal analysis was conducted assuming that they were exposed to the standard fire curve. Secondly, the sectional analyses were performed for the reinforced concrete element sections and moment-curvature relations were obtained. Finally, the three dimensional (3D) structural system was modeled and static pushover analysis was carried out in accordance with the Turkish Building Earthquake Code (TBEC 2018). The results showed that as the exposure time to high temperature increase the inelastic displacement capacity and the base shear force values decrease. The results were also affected by the location of the fire event. Besides, plastic hinges occurred more quickly than the situation before fire event, resulting in a decrease in the load carrying capacity and stiffness of the system.