Seismic Performance and Stress Transferring Mechanism of Through-Column-Type Joints for Composite Reinforced Concrete and Steel Frames

A total of three beam-to-column joints for composite structural systems consisting of reinforced concrete columns and steel (RCS) beams, which are referred to as “composite RCS systems,” were tested to investigate the structural performance and the stress transferring mechanisms as a part of the studies on “Composite and Hybrid Structures” of the U.S.–Japan cooperative earthquake research program, which started in April 1993 as a five-year research program. The joint details examined were “through-column type,” of which the joints are reinforced by cover plates and horizontal stiffeners without beam flanges. This paper indicates that the use of thicker cover plates and extended face bearing plates are effective to enhance the structural performance of the joints. Stress transferring mechanisms in the joints are also discussed using three macromodels.