Behavior of the anchors of the method by inserting bars Fibre reinforced shear reinforcement for polymers reinforced concrete beams

The embedded through-section (ETS) technique was recently developed to avoid the debonding failure that occurs with other fiber-reinforced polymer (FRP) strengthening techniques such as the externally bonded (EB) and near-surfacemounted (NSM) methods. The method offers greater confinement and leads therefore to a substantial improvement in bond performance. In addition, it requires less concrete preparation than the other strengthening techniques. In this study, experimental results from 13 direct-shear test specimens are reported. The influence of the following major parameters on the bond behaviour of FRP-strengthened reinforced concrete beams is examined: concrete strength, hole diameter, bar diameter, bar surface area, and bar bond length. The experimental results show that debonding can be avoided by providing a sufficient bar length and high concrete strength. Among the analytical models suggested in the literature for the bond behaviour of FRP reinforced concrete, the BPE modified model and the CMR model are compared with the experimental results obtained here. The CMR model with new fitting parameters is found to be an accurate way of simulating the experimental results.