EXPERIMENTAL STUDY ON DAMAGE OF SRHSHPC FRAME BEAMS UNDER LOW CYCLE REVERESED LOADING

The process of damage evolution of steel reinforcement high strength high performance concrete (SRHSHPC) frame beams was studied through low cycle reversed loading experiment on 5 frame beam specimens with various steel ratios and stirrups ratios. The crack development and failure model of frame beam specimens were analyzed, while the loading-displacement hysteretic curves and skeleton curves of frame beams were obtained. The law and characteristics of the strength and stiffness degradation, ductility and energy dissipation capacity of frame beams with different steel ratios and stirrups ratios were studied. The result indicates that the SRHSHPC frame beams subjected to low cycle reversed loading produce flexure failure normally by reasonable design, and exhibits good ductility and energy dissipation capacity. As the increase of cycle number and horizontal displacement amplitude, the damage of specimens is accumulated gradually, which causes degradation in strength and stiffness and decrease of energy dissipation capacity. However, the strength and stiffness degradation amplitude are decreased, while the energy dissipation capacity is improved by increasing stirrups ratios and steel ratios. The research will provide experimental support for establishing seismic damage model and further revealing the effect of damage on mechanical property of SRHSHPC frame beams.