Seismic behaviour of post-tensioned precast concrete beam-column connections

In a post-tensioned precast concrete beam-column connection, the precast beams are post-tensioned to ensure the integrity of the connection and to provide recentring characteristics when the connection is subjected to seismic loads. In this study, the post-tensioned precast concrete beam-column connections were tested under reverse-cyclic loading with the test variables of grout strength at the beam-column interface and prestressing stress of stands. The test results showed that the post-tensioned precast concrete beam-column connections have a seismic performance equivalent to that of a conventional reinforced concrete beam-column connection. When high prestress is applied, however, confinement reinforcement is required at the beam ends to secure sufficient deformation capacity without crushing of concrete. An analysis model for post-tensioned precast concrete beam-column connections is also proposed; the model considers the bond properties of prestressing strands, and provides good agreement with the experimental results.