Shear behavior of basalt fiber reinforced polymer (FRP) and hybrid FRP rods as shear resistance members

This paper investigates the shear properties of basalt fiber reinforced polymer (BFRP) and the hybrid FRP rods as shear resistance members. The shear properties of FRP rods and the corresponding resin casting rods were studied separately, including variables representing rod diameters of 4-16 mm, resin types of epoxy and vinyl ester resins and fiber types comprising basalt, carbon and their hybridization. The ratio between shear stress and shear deformation was first described according to experimental results, and the shear contribution mechanism was clarified for different stages. An equation for predicting the shear strength of BFRP and hybrid FRP rods was proposed by discussing the influence of different variables. The results show that the shear strength and shear deformation ratio of different FRP rods is maintained almost constantly regardless of the variation in diameters, resin types and fiber types. The major shear resistance in FRP rods is contributed by the internal fibers, whereas the resin contributes only 8% of the overall strength and acts only in the first stage. A three-stage model is proposed to describe the entire stress to deformation ratio. A derived equation based on the shear contribution analysis is also used to predict the shear strength of the BFRP and hybrid FRP rods with high accuracy.