Experimental study on post-fire behaviour of a novel assembled wall-slab joint

In this study, the post-fire behaviour of a novel assembled wall-slab joint with high-performance concrete (HPC) post-casted in the core area was experimentally investigated. Fire and post-fire monotonic static loading tests were performed on three full-scale specimens, including two assembled joints and one cast-in-place joint for comparison. The temperature distribution inside the joints exposed to fire, failure displacement and failure mode of the joints after a fire, and residual bearing capacity of the joints are discussed. The results show that the assembled wall-slab joints are more integral than the cast-in-place joints after a fire. In addition, HPC can effectively reduce the temperature in the core area of an assembled joint exposed to fire and improve its post-fire stiffness. The failure modes of the two types of joints were also different. The residual bearing capacity of the assembled wall-slab joint after 1.5 h of heating was approximately 22.3% lower than after 1 h of heating. In addition, the residual bearing capacity of the assembled wall-slab joint was approximately 28% larger than that of the cast-in-place wall-slab joint at the same heating time of 1.5 h. In general, the assembled wall-slab joint showed better performance than the cast-in-place joint both during and after a fire.