Shear capacity of fiber-reinforced polymer-strengthened reinforced concrete beams: Fiber reinforced polymer rupture

A recent innovation in shear strengthening of reinforced concrete beams is to externally bond fiber-reinforced polymer (FRP) composites. Many studies have been undertaken on this strengthening technique. These studies have established clearly that such strengthened beams fail in shear mainly in one of the two modes: FRP rupture and FRP debonding, and have led to preliminary design proposals. This paper is concerned with the development of a simple, accurate, and rational design proposal for the shear capacity of FRP-strengthened beams which fail by FRP rupture. To this end, existing design proposals are reviewed, and their efficiencies highlighted. A new strength model is then developed, which recognizes the fundamental characteristics of FRP. The model is validated against experimental data collected from the existing literature. Finally, a new design proposal is presented.