Shear Behavior of Reinforced Concrete T-Beams with Externally Bonded FiberReinforced Polymer Sheets

This research studies the interaction of concrete, steel stirrups, and external fiberreinforced polymer (FRP) sheets in carrying shear loads in reinforced concrete (RC) beams. A total of eight 600 mm high T-beam tests are reported. Three types of FRP were applied externally to strengthen the web of the T-beams: uniaxial glass fiber; uniaxial carbon fiber; and triaxial glass fiber. The test results show that FRP reinforcement increases the maximum shear strengths from 77.4 to 117.3% over beams with no FRP. The magnitude of the increased shear capacity is dependent not only on the type of FRP, but also on the amount of internal shear reinforcement. The FRP strains were found to be uniformly distributed among the fibers crossing the concrete shear crack. This paper also presents a design model based on the failure mechanisms of the test specimens. Good agreement was obtained between test and predicted results by using the proposed model.