Experimental study on seismic behavior of steel reinforced recycled concrete columns with high axial compression ratio

To study the seismic behaviors of full-scale steel reinforced recycled concrete columns under high axial compression ratio, the columns with three types of recycled coarse aggregate replacement rate under different axial compression ratios were designed, and four specimens were experimented on the 40 000 kN multi-function testing machine under low cyclic reversed loading. The influences of different design variables on horizontal load bearing capacity, hysteretic behavior, skeleton curves, energy dissipation, deformation and stiffness degradation of specimens were obtained after observing the mechanical processes and failure patterns. The results show that the ultimate failure pattern of the four specimens is the bending-shear failure and the hysteresis loop of each column is relatively plump, indicating that the columns show good energy dissipation behavior. The increase of the recycled coarse aggregate replacement rate decreases the deformability, but it has little influence on the bearing capacity and stiffness degradation of the specimens. With the increase of axial compression ratio, the load-bearing capacity, stiffness and energy dissipation behavior of specimens raise, but the stiffness and bearing capacity degradation intensifies and the ductility declines acutely. The steel reinforced recycled concrete columns with high axial compression ratio can still maintain good seismic performance, and this study provides the basis for subsequent theoretical research and practical engineering application. © 2018, Editorial Board of Journal of Harbin Institute of Technology. All right reserved.