EXPERIMENTAL STUDY ON THE RESTORING FORCE MODEL OF STEEL REINFORCED RECYCLED CONCRETE FRAME INFILLED WITH RECYCLED CONCRETE BLOCKS

Based on the experimental study on seven 1/2.5-scaled model of one-bay and one-story steel reinforced recycled concrete frames infilled with recycled concrete blocks under low cyclic reversed loading, the effects of infilled walls' arrangement, masonry material, the vertical spacing of tie bar, axial compression ratio, and the ratio of width to height of infilled wall on seismic behaviors were analyzed. The typical final failure mode, load-displacement curves, load carrying capacity and displacement ductility were also analyzed. The results indicate that the failure mechanism is the beam-hinged mechanism, and the higher filling rate of infilled wall can reduce the damage degree of the whole structure. With the increment of the filling rate of infilled wall, the increase will happen for the infilled blocks strength, the axial compression ratio and the number of tie bar, loading carrying capacity and initial stiffness. The mean value of displacement ductility is 6.26, which shows the strong capacity of resisting collapse. Based on the experimental results, a four segments restoring force model for the structure was proposed, and can provide theoretical foundation for the nonlinear seismic analysis of a steel reinforced recycled concrete frame infilled with recycled concrete blocks.