Experimental Study On Seismic Resistance Of PVA-FRCC Medium - Long Column With Reinforcement Under Low Cyclic Load

Abstract

In order to improve the deformation performance and damage tolerance of frame columns under seismic load and optimize the seismic performance of frame columns, using polyvinyl alcohol fiber reinforced cement-based composite (PVAFRCC) instead of ordinary concrete is one of the effective ways. At present, many scholars' research on the seismic performance of PVA-FRCC columns mainly focuses on short columns with high axial compression ratio or using PVA-FRCC instead of ordinary concrete in beam column joints. Based on this, considering the influence of axial compression ratio, shear span ratio and longitudinal reinforcement ratio on the seismic performance of PVA-FRCC medium-long columns, seven medium-long columns with fiber volume content of 1% were designed in this paper. Through quasi-static test, the crack development of the specimens under low cyclic loading was observed, and their hysteretic behavior, skeleton curve Degradation of energy dissipation capacity and bearing capacity. The test results showed that each medium-long column has good ductility bending failure, and the concrete protective layer does not fall off during failure. Increasing the axial compression ratio can improve the cracking load, yield load and peak load of PVA-FRCC columns, but the ductility and energy dissipation capacity are reduced. At the same time, it can reduce the number of cracks and limit the width of cracks; With the increase of shear span ratio, the bearing capacity of PVAFRCC columns decreases, but the deformation capacity and energy dissipation capacity are greatly improved; With the increase of reinforcement ratio, the bearing capacity, ductility and energy dissipation capacity of PVA-FRCC columns are improved, and the degradation rate of stiffness and bearing capacity is slowed down, which can effectively improve the seismic performance of members; The shear span ratio and axial compression ratio have a great influence on the seismic performance of FRCC columns.