Experimental study on shearing capacity of concrete beams longitudinal reinforced with steel fiber composite bars and BFRP bars

To investigate the shearing capacity of concrete beams longitudinally reinforced with steel fiber composite bars (SFCBs) and basalt fiber reinforced plastics (BFRP) bars respectively, shearing capacity tests of 46 specimens were designed and conducted. Beams reinforced with steel bars were also tested for comparison. The experimental parameters include shear span ratio, longitudinal reinforcement ratio and the existing of stirrups. The test results demonstrate that the shearing capacity of beams with each type of longitudinal reinforcement increases with the decrease of shear-to-span ratio. The shearing capacity of SFCB beams increases with longitudinal reinforcement ratio. Further, to evaluate the contribution of longitudinal SFCBs and BFRP bars to the shearing capacity of the concrete beams, the concept of generalized dowel action influence coefficient was put forward and the corresponding calculation formula was derived. Based on the coefficient, a shearing capacity formula for concrete beams with longitudinal SFCBs or BFRP bars was put forward, and the validity of the formula was verified using 223 shear test results of concrete beams reinforced with steel bars, BFRP bars and SFCBs. Further, referring to the safety level of the formulae proposed in codes for the shear capacity of concrete beams reinforced with steel bars, the design formula for the shearing capacity of concrete beams reinforced with SFCBs and BFRP bars was proposed.