Fiber reinforced polymer shear strengthening of reinforced concrete beams with transverse steel reinforcement

The paper aims to contribute to a better understanding and modeling of the shear behavior of reinforced-concrete RC beams strengthened with carbon fiber reinforced polymer FRP sheets. The study is based on an experimental program carried out on 11 beams with and without transverse steel reinforcement, and with different amounts of FRP shear strengthening. The test results provide some new insights into the complex failure mechanisms that characterize the ultimate shear capacity of RC members with transverse steel reinforce- ment and FRP sheets. After the discussion of the above topics, a new upper bound of the shear strength is introduced. It should be capable of taking into account how the cracking pattern in the web failing under shear is modified by the presence of FRP sheets, and how such a modified cracking pattern actually modifies the anchorage conditions of the sheets and their effective contribution to the ultimate shear strength of the beams.