Seismic Behavior of Hybrid Concrete Beam-Column Connections with Composite Beams and Cast-in-Place Columns

The objective of this study is to develop a new type of moment-resisting hybrid beam-column connections that are economical and could be easily constructed. The new type of moment-resisting hybrid concrete beam-column connections proposed for the seismic region consisted of cast-in-place (CIP) concrete columns and composite concrete beams with precast U-shaped beams. An experimental study of two full-scale hybrid concrete beam-column connections with composite beams and CIP columns, including an exterior and interior connection and two control CIP connections under reversed cyclic loading, is presented. Results revealed that two hybrid concrete beam-column connections, as expected, exhibited a strong-column/weak-beam failure mechanism, and were capable of matching the performance of monolithic connections. Test specimens behaved in a ductile manner, and exhibited stable hysteresis loops. The difference in load-carrying capacity between the hybrid concrete connections and their control specimens was less than 10%. A restoring force model was developed based on the test results.