Experimental Study on Seismic Behavior of Precast Assembled Steel-Concrete Beam-Column Composite Joint

A new type of precast assembled steel-concrete beam-column composite joint with improved seismic and construction efficiency was proposed. Three composite-joint specimens were tested through pseudo-static test to evaluate the seismic behavior of the composite joints. Axial compression ratio was used as the test parameter, with selected values of 0.18, 0.36, and 0.54. The analysis of experimental results revealed the excellent seismic performance of the proposed joint. In addition, the failure mode was the shear failure of the connection zone, which consisted of the precast concrete beam and beam connecting plate. The proposed joint attained equivalent viscous damping coefficients ranging between 0.149 and 0.180 and ductility greater than 2. The results demonstrate the higher elastic deformation capability and collapse resistance of the composite joints than those of cast-in-place concrete joints. The increase in the axial compression ratio had a positive effect on enhancing the bearing capacity of the proposed joint. The peak load of the composite-joint specimens was increased by 28.41% compared with other specimens. However, the capability to resist cyclic load was weakened, and the rate of stiffness degradation was accelerated. The research conclusions can provide theoretical guidance to optimizing the seismic design of beam-column composite joints.