Flexural Strengthening of Reinforced Concrete Beams Using Fasteners and FiberReinforced Polymer Strips

Current methods of flexural strengthening of reinforced concrete beams with fiberreinforced polymer (FRP) strips require time-consuming and often difficult preparation to provide adequate bond strength between the FRP strip and the concrete substrate. This paper presents a feasibility study of an alternative method of attaching FRP strips to reinforced concrete beams. The method utilizes off-the-shelf powder-actuated fasteners to attach pultruded FRP strips to the concrete. Small-sized beams strengthened with this method were tested, and the results were compared with the results from beams strengthened with conventional bonding methods and to the results from control beams. Small-size beams strengthened using powder-actuated fasteners attained 65 to 70% of the increase in capacity of the beams strengthened using the conventional bonded method; however, the fastening method is extremely rapid and the failure modes of the beams strengthened by the fastening method were more ductile than those strengthened by the bonded method.