Abstract

Deterioration of civil engineering infrastructure may be attributed to the aging, environmentally induced degradation, poor initial design and/or construction, lack of mainte-nance, change of use, more stringent design criteria and natural events such as earthquakes. Non-corrosive fiber reinforced polymer (FRP) reinforcement have recently made major break-throughs in civil engineering applications. FRP rehabilitation is a cost-effective, state-of-the-art technology in the repair and strengthening of structures. Use of Carbon Fiber Reinforced Poly-mer (CFRP) Plates, as externally bonded reinforcement, is a practically efficient and technically sound method of strengthening and upgrading structurally inadequate or otherwise damaged or deteriorating reinforced concrete (RC) members. Externally bonded plates help in improving the structure performance by reducing deflections or cracking and increasing ultimate strength. The ultimate capacity of the strengthened beam is controlled by either compression crushing of con-crete, rupture of the composite plate, local failure of concrete at the plate end due to stress con-centrations and flexural shear crack-induced debonding of Concrete-CFRP interface. Another factor that could affect the ultimate strength and mode of failure is the shear span. These failure modes along with the variation of shear span were considered in this study to investigate the ul-timate load carrying capacity and failure modes of strengthened beams. Beams with U-shaped anchorages were tested in four point bending to determine the ultimate load carrying capacities of the beams. Properly placed U-shaped anchorages at plate cut-off points and along the span were shown to be effective in optimizing the deformability and strength characteristics of CFRP strengthened RC beams in flexure and shear.