Experimental investigation on shear beahvior of PVC-CFRP confined reinforced concrete beams

This paper presents an experimental investigation on the effects of shear span ratio, stirrup ratio, number of annular carbon fiber reinforced plastics (CFRP) and longitudinal CFRP sheets on the shear stiffness of polyvinyl chloride (PVC)-CFRP confined reinforced concrete beams (PCRCBs). A total of 11 PCRCBs with a cylindrical cross-section and a length of 1500 mm were designed and fabricated for four-point bending tests. The experimental results indicated that the stiffness and ultimate bearing capacity of specimens decreased with the decrease of shear span ratio or the increase of shear span ratio. Conversely, an increase in the number of CFRP strip layers and CFRP sheets led to enhancements in the initial stiffness, the stiffness during the stabilization phase, and the ultimate bearing capacity. Additionally, this increase in CFRP layers slowed down the rate of stiffness degradation. Based on the experimental results, formulas for calculating the short-term stiffness and predicting the deflection of PCRCB were derived by combining the curvature method. The accuracy of the formula was verified to be consistent with the experimental data.