EXPERIMENTAL RESEARCH ON ASEISMIC BEHAVIOR OF HIGH DUCTILE CONCRETE FILLED STEEL PLATE COMPOSITE COUPLING BEAMS

To improve the aseismic behavior of coupling beams with a small span-to-depth ratio, high ductile concrete (HDC) is used to replace the concrete. Two HDC filled steel plate composite coupling beams, one concrete filled steel plate composite coupling beam and one HDC steel plate composite coupling beam, were designed. The failure pattern, deformation capacity and energy dissipation capacity of composite coupling beams were studied by the quasi-static tests. The experimental results show that the deformability and damage-tolerance of the steel plate composite coupling beams can be improved by replacing concrete with HDC. The synergistic performance of HDC and steel webs is good, which is beneficial to the shear effect of steel webs. The energy dissipation of the HDC filled steel plate composite coupling beams is significantly higher than those of the concrete filled steel plate composite coupling beam and of the HDC steel plate composite coupling beam. The design values of shear-compression ratio of the HDC filled steel plate composite coupling beams is 0.65-0.70, which is obviously higher than that of the HDC steel plate composite coupling beam. Therefore, the shear-compression ratio limitation of the coupling beams can be improved by using the HDC filled steel plate composite coupling beams, and the problem of shear-pressure ratio ultra-limit of coupling beam in design can be solved.