Study on two types of joints of steel-concrete composite beam and reinforced concrete column

Two new types of joints for a steel-concrete composite beam and reinforced concrete column are presented, the detailing of the joints is as follows: The reinforced bar in the concrete of composite beam runs through the core zone of joint in both types of joints, but the joist steel of the composite beam is connected by straight reinforced bar and X shaped reinforced bar in one type of joint, and connected by the endplate with stiffener and long shank bolts in the other type of joint. The force transmission paths in both types of joints are explicit, and it is convenient to pour core zone concrete. In order to study the seismic behavior and failure mechanism of the joints, quasi-static tests were carried out on full-scale specimens and simulating the joint's core zone specimens. Plastic hinges formed in the beam end of full-scale specimens before failure in the test. The joints' strength, ductility and hysteresis behavior are analyzed, and results indicate the joints have excellent energy dissipation capacity. The shear capacity formula of the core zone is presented according to the test.