Seismic Behavior of Precast and Post-Tensioned Exterior Connections with Ductile Headed Rods

This study experimentally investigates the seismic structural performance of ductile bolted connectors and unbonded post-tensioning tendons for exterior precast concrete (PC) beam-column connections. Three full-scale beam-column subassemblies-a monolithic reinforced concrete (RC) connection conforming with ACI 318-19, a PC connection with ductile rods, and a PC connection with ductile rods and post-tensioning-were fabricated for quasi-static cyclic loading tests. The PC specimens exhibited stable lateral load resistance up to +/- 4% inter-story drift, with concentrated inelastic deformation within the ductile rods per the intended design concept. After reaching their peak lateral loads, the PC specimens experienced strength degradation comparable to the RC specimen, demonstrating that they are adequate for a lateral load-resisting system. The prestressing force induced by the post-tensioning was found to be effective at improving flexural and shear strength of the beam-column connection and at reducing the pinching effect observed at the beam-column interface of the PC specimens.