Shear Strengthening of Reinforced Concrete Beams Using Fiber-Reinforced Polymer Sheets with Bonded Anchorage

This paper presents results of a study into shear strengthening of reinforced concrete (RC) beams using externally bonded fiber-reinforced polymer (FRP) sheets. The study focused on the effect of extending the length of sheet on the top surface of the beam to delay or prevent sheet debonding. Test variables were the kinds of fibers, the wrapping layouts, and the length of bonded anchorage. From the experiments, it was confirmed that FRP with bonded anchorage is much more effective than the U-wrap scheme. Extending the sheets on a top surface of the beam resulted in a decrease in interface bond stresses and an increase in FRP strain at failure. Four different models for estimating the contribution of FRP sheets to the shear capacity V-sub-f of beams were investigated. Two new equations to calculate V-sub-f are given: when failure occurs due to sheet debonding and when the beams are provided with bonded anchorage at the top face of beams.