Full-scale experiment on seismic performance of damaged self-centering concrete joints after post-earthquake fire

Self-centering concrete joints are an increasingly acceptable mean to sustain earthquake loadings in structures. Whilst seismic performance of self-centering concrete joints is extensively researched, the post-fire seismic performance of self-centering concrete joints is rarely reported. A better understanding of the performance for fire-damaged self-centering concrete joints is necessary to assess the effects of post-earthquake fire on structures incorporating self-centering joints. An experimental study was conducted to investigate the residual capacity of self- centering concrete joints subjected to post-fire earthquake. In total, three self-centering concrete joints were tested to investigate the post-fire seismic performance. One joint was heated to obtain fire damage. One damaged joint was exposed to a post-earthquake fire. Finally, one undamaged joint and two post-fire joints were subjected to cyclic loading. Based on the fire test results, fire responses including thermal response and damages during fire and after fire were investigated. Then, a followed discussion of seismic performance of those post-fire joints was presented. The control joint without heat exhibited excellent seismic performance with negligible residual displacement. Both post-fire joints performed well after exposure to 170 min of ISO-834 standard fire. Undoubtedly, the fire damages and post-earthquake fire damages have a considerable effect on the post-fire seismic performance of self-centering joints. However, the damages induced by cyclic loadings at the drift ratio of 2% before fire test have marginal influence on the seismic performance of post-fire self-centering joint. The experimental data can be subsequently utilized to evaluate the residual capacity of self-centering concrete joints after fires.