Experimental study on PVC-CFRP confined concrete columns under low cyclic loading

This paper presented an experimental study on the failure mode, ultimate bearing capacity and ductility capacity of PVC-CFRP confined reinforced concrete columns subject to low cyclic loading. Several parameters, such as the axial compression ratio, shear span ratio, and hoop spacing of CFRP strips were considered in the analysis. The results showed that all columns at low axial compression ratio failed by bending. The long and short columns with large hoop spacing at high axial compression ratio failed by flexural shear while the short columns with small hoop spacing at high axial compression ratio failed by shear. The ultimate bearing capacity increased as the axial compression ratio increased or the shear span ratio decreased while the ultimate bearing capacity decreased as the hoop spacing of CFRP strips increased. The ultimate strains located at the bottom of the column increased as the axial compression ratio increased while the ultimate strains decreased as the shear span ratio increased. The confining effect of CFRP strips increased gradually as the hoop spacing of CFRP strips decreased. The ductility capacity decreases as the axial compression ratio or the shear span ratio increased while the ductility capacity increases as the hoop spacing of CFRP strips increased.