Post-earthquake fire resistance of self-centering concrete beam-column joint: An experimental investigation

Fire is an accidental disaster resulting in disastrous consequences for building. Post -earthquake fire is a secondary disaster induced by earthquake, triggering off larger destruction in a higher probability of occurrence. The potential severity of consequences to structures makes fire and post -earthquake fire safety imperative in the design of any new structures. Self -centering concrete joints are introduced as a promoting alternative to traditional reinforced concrete (RC) joints. They always exhibit excellent seismic performance and self -centering capacity, available in high -seismic zone. However, the current lack of experimental data on fire response of self -centering concrete joints means that they remain an open issue in current design codes. In this paper, fullscale quasi -static cyclic test and fire tests were conducted on two self -centering concrete joints connected with bolted angles and posttensioned (PT) tendons. The experiments aimed to explore the performance of selfcentering joint in fire situations, and the impact of post -earthquake damages on fire response of self -centering joint. The deformation patterns and thermal responses of self -centering joints including temperature distribution, prestress force of PT tendons, displacements at beam ends and duration were recorded and analyzed. The results show that both self -centering joints exhibited satisfactory fire resistance with endurance over 170 min. Generally, the bolted angles and PT tendons in self -centering concrete joints showed acceptable working performance in fire. The findings unveil the actual response of self -centering concrete joints during the fire and postearthquake fire conditions, providing experimental data for further numerical simulation and analysis. It can be used to calibrate the design approach for self -centering joints under fire and seismic -induced fire exposure.