Experimental Investigation on the Seismic Behavior of Precast Concrete Beam-Column Joints with Five-Spiral Stirrups

Precast concrete structure is a low-carbon building system that has been attracting extensive attention in recent decades. Beam-column joints are the weak links in precast concrete structures. Past studies showed that the five-spiral stirrups had excellent confinement effects and had the potential to enhance the seismic performance of concrete structures. This study proposed the reinforcement of precast concrete beam-column joints by using five-spiral stirrups and investigated their seismic performance. Considering the influences of the joint failure mode, joint type, construction method, and stirrup type, low-cycle loading tests were conducted on six full-scale precast concrete beam-column joint specimens. Various seismic behavior indicators, such as failure modes, hysteresis curves, skeleton curves, ductility, and energy dissipation, were obtained. The results indicated that the deformation capacity of the precast joints with five-spiral stirrups was comparable to that of cast-in-place joints. Under different failure design criteria, the seismic performance of the precast joints was superior to that of cast-in-place joints. Furthermore, the experimental capacities of the precast joints, using five-spiral stirrups, were higher than the calculated values according to the design code, demonstrating an adequate safety margin. This research contributes to the development of low-carbon and sustainable construction practices in the field of precast concrete structures.