Seismic performance of emulative precast concrete beam–column connections with alternative reinforcing details

Abstract

This article presents an experimental investigation on alternative reinforcing details for the bottom bars of precast concrete beams at cast-in-place beam–column joints to achieve the behaviour as for monolithic reinforced concrete beam–column connections. To relieve steel congestion and fabrication difficulties, it is proposed to use headed bars for the bottom bars that are protruded from precast beams and anchored in the middle of the beam–column joint. In total, six interior beam–column connection specimens were tested under reversed cyclic loading. The primary test variables were the transverse beams and the anchorage of the bottom beam bars in the joint. Hysteretic behaviour, including strength degradation, stiffness degradation and energy dissipation, was evaluated in accordance with the acceptance criteria for special moment-resisting frames. Test results demonstrated that emulative precast concrete specimens with bottom beam bars anchored in the joint middle can perform as well as monolithic beam–column connections with continuous beam bars passing through the joint. On the basis of the experimental results, design recommendations are drawn for these types of emulative precast beam–column connections.