Experimental and finite element investigation of the shear performance of BFRP-RC short beams

This paper reports on the experimental, analytical, and numerical results of deep concrete beams reinforced with basalt fiber-reinforced polymer (BFRP) bars without web reinforcement. Ten beams of 2.0 m long and rectangular cross sections of 140 mm width with and variable heights were tested under four-point loading configuration. Three beams were reinforced with steel bars to act as controls while the other beams were reinforced with BFRP bars. The investigated parameters included the effective depth, d, the longitudinal reinforcement ratio, rho, and the shear span-to-depth ratio, a/d. All of the BFRP-reinforced beams recorded slightly higher load-carrying capacities but lower post-cracking stiffness than their steel-reinforced counterparts. The strut-and-tie model of CSA-S806-12 conservatively predicted the shear capacities of the BFRP-reinforced beams whereas that of ACI-318-14 overestimated the capacities of most of the beams. A finite element model was developed using ABAQUS to predict the behavior of the tested beams. The model adequately predicted the shear capacities of the beams and captured well their failure modes. The verified FE model was used to expand on the experimental test matrix and include additional beams to further investigate a wide variation of the experimental parameters. The results indicated that the shear capacities of BFRP-reinforced beams were linearly proportional to the cubic root of the effective depth, (3)root d, the longitudinal reinforcement ratio, (3)root rho, and the reciprocal of the shear span-to-depth ratio, 1/(3)root(a/d), which was in agreement with the provisions of CSA S806-02. Furthermore, a linear correlation between the shear capacities and the square root of the effective depth root d was observed indicating a good correlation with the provisions of ACI-440.1R.