Seismic Behavior and Design of Unbonded Post-Tensioned Precast Concrete Frames

Unbonded post-tensioned precast concrete beamcolumn subassemb!ages have been studied in previous research and were found to be a promising seismic resistant structural system. The behavior of two six-story unbonded post-tensioned frames is studied using nonlinear push-over static analyses and time-history dynamic analyses. Two analytical models are developed for the analyses; the fiber model and the spring model. The results show that the behavior of unbonded posttensioned precast frames, in particular, the strength, ductility, and self-centering capability, is more than adequate-tor severe earthquake hading.