1.Jiangsu University;2.Southeast University
The steel-basalt fiber composite bar (SFCB) has the advantages of the ductility of steel bar and the corrosion resistance of basalt fiber, and has significant secondary stiffness as well. However, SFCB’s elasticity modulus is lower than that of the steel bar. The application of SFCBs as longitudinal reinforcement bars enables the flexural properties of concrete members to present secondary stiffness, but the shear capacity of the members will be reduced, compared with that of steel reinforced concrete beams. In this paper, four-point loading experiment of the beams longitudinal reinforced with SFCBs were carried out, takeing the following variables of the specimens into consideration: the type of longitudinal reinforcement, longitudinal reinforcement ratio and the shear span ratio. The influence of the above variables on the shear failure modes, the development of diabonal cracks, and shear force capacity of the above concrete beams were analyzed and summarized in detail. The research revealed the following three main results. The failure modes of the SFCB beam were mainly described as diagonal-compression failure, shear-compression failure and atypical shear-compression failure. The shear force capacity of SFCB beams was lower than that of steel reinforced beams. The diagonal cracks of SFCB reinforced beams were wider than those of steel reinforced beams. Based on the truss arch model, the shear force capacity formula of SFCB beams is derived. The calculating results of the formula agree well with the experimental ones with fairly applicability and safety.