Finite element parametric study of reinforced concrete beams shear-strengthened with embedded FRP bars

The deep embedment (DE) of fibre-reinforced polymer (FRP) bars is a promising shear-strengthening scheme for existing concrete structures. In the current study, a three-dimensional nonlinear finite element (FE) model for DE-strengthened reinforced concrete beams was developed and validated. The FE and Concrete Society TR55 predictions were compared with published experimental results. The FE-predicted/experimental shear strength enhancement ratio is 1.08 with a standard deviation of 0.25, whereas the TR55-predicted/experimental shear strength enhancement ratio is 1.57 with a standard deviation of 0.54. A numerical parametric study was carried out. The results showed that the predicted shear strength enhancement was positively influenced by the use of inclined DE FRP bars and the increase in concrete compressive strength but decreased with the increase in shear span-to-effective depth ratio and internal steel stirrup-to-DE FRP bar ratio. The predicted percentage of shear strength enhancement was not significantly influenced by size effect.