EXPERIMENTAL STUDY ON THE SEISMIC BEHAVIOR OF SHORT-PIER SHEAR WALLS SUBJECTED TO FREEZE-THAW CYCLES

To study the influence of freeze-thaw cycles, the concrete strength grade and axial compression ratio on the seismic behavior of short-pier shear walls (SPWs) with rectangular sections and investigate the limits of axial compression ratio of SPWs, 6 SPW specimens with shear span ratio of 1.14 were subjected to 200 freeze-thaw cycles in artificial climate room before quasi-static tests were conducted. Based on the experimental results, the failure process and patterns of the SPW specimens are described. Six performance indicators, that is, the load-carrying capacity, ductility, plastic rotation, strength deterioration, stiffness degradation and cumulative hysteretic energy dissipation, are used to evaluate the deterioration law of the seismic behavior of SPW. The results show that the freeze-thaw cycles have a great effect on the load-carrying capacity, strength deterioration, stiffness degradation and cumulative hysteretic energy dissipation of SPWs, whereas the deformation capacity of SPWs is less influenced by the freeze-thaw cycles. While the number of freeze-thaw cycles remains the same, increasing the strength grade of concrete can enhance the frost resistance and improve the seismic behavior of SPWs. In freeze-thaw environment, the axial compression ratio of SPWs should be strictly controlled.