Seismic tests of precast concrete, moment-resisting frames and connections

This paper presents the results of experimental investigations on four full-scale precast concrete connections and a half-scale, two-story, two-bay, precast concrete, moment-resisting frame, which consisted of composite concrete beams and cast-in-place concrete columns, under cyclic loading. The precast concrete connections investigated in this paper included an exterior connection, an interior connection, a T connection, and a knee connection. Test results revealed that the four precast concrete connections, as expected, exhibited a strong column-weak beam failure mechanism and failed due to concrete crushing and fracturing of longitudinal bars as a result of forming a plastic hinge at the fixed end of the beam. The four connections behaved in a ductile manner. However, the displacement ductility of the knee connection was the poorest among them. The precast concrete frame exhibited a mixed side-sway mechanism and behaved in a ductile manner. The hysteresis curves of the frame were full and exhibited good energy-dissipation capacity. The global and interstory displacement ductility of the frame was not less than 4.5. In general, the seismic behavior of the precast concrete frame was satisfactory. This research could provide structural engineers with useful information about the safety of precast concrete-frame structures.