Shear failures of reinforced concrete (RC) structural elements are catastrophic and occur with no advance warning. Conventional shear strengthening methods like external post tensioning, member enlargement along with internal transverse steel, and bonded steel plates are time consuming and complex. Shear strengthening with the help of advanced composite materials, known as fiber reinforced polymer (FRP), offers significant advantage over the conventional methods in terms of cost and time. The overall goal of this study was to investigate the shear performance and modes of failure of RC T-shaped joists strengthened with externally bonded FRP sheets. In order to achieve this goal, an experiment consisting of testing of twenty, full-scale RC joists was carried out at the Malcolm Bliss Hospital, St.Louis, Mo. The selected building was completed in 1964 and provided an ideal test bed for carrying out experiments on an existing structure. To date research in strengthening has been restricted to laboratory experimentation. As part of the research program, the study examined the effectiveness of FRP reinforcement in enhancing the shear capacity of RC joists. Furthermore, an innovative end anchor system, which allowed a better exploitation of the strengthening system, was also tested.

The experimental results indicated that externally bonded FRP can be used to enhance the shear capacity of a member. An attempt has been made to validate the existing design guidelines for shear strengthening using the data obtained in this research.