BEHAVIOR OF JOINT OF GANGUE CONCRETE-FILLED STEEL TUBULAR COLUMN WITH REINFORCED GANGUE CONCRETE BEAM UNDER LOW-CYCLIC LOADS

Joint of gangue concrete-filled steel tubular column with reinforced gangue concrete be-am was studied, with continuous longitudinal reinforcement through interior joint, and anchored longitudinal reinforcement in exterior joint. The tests of joint of gangue concrete-filled steel tubular column with reinforced gangue concrete beam, under low-cyclic loads, were carried out. Tests were made on hydraulic servo system (MTS Systems Inc, U.S.) with automatic data acquisition, and the reliability of joints was validated by observing the main failure model, working behavior, hysteretic behavior. The analysis showed that load-displacement hysteretic curve of beam end is plumper, ductility and energy dissipation capacity of joint is better and seismic behavior is good, meeting seismic design requirements. Because of the existence of continuous members, internal forces transferred to concrete core from beam end effectively, and global stiffness and seismic behavior of the structures enhanced. Compared with the dead weight of concrete-filled steel tubular structure, gangue concrete-filled steel tubular structure is less by 20%, for apparent density of gangue concrete is less than concrete. In addition, coal gangue as aggregate will save nonrenewable resources, reduce environmental pollution, and promote the sustainable utilization of the natural resources.