Flexural Strengthening of Reinforced Concrete Beams Using Fasteners and Fiber-Reinforced Polymer Strips

Existing methods of flexural strengthening of reinforced concrete beams (RCBs) with fiber-reinforced polymer (FRP) strips require time-consuming and often difficult preparation to yield adequate bond strength between the FRP strip and the concrete substrate. This research presents a feasibility study of an alternative method of attaching FRP strips to RCBs. Off-the-shelf powder actuated fasteners are used to attach pultruded FRP strips to the concrete. Small-sized RCBs strengthened with this method were tested, and the results were compared with those from beams strengthened with conventional bonding methods and to results from control beams. Small-size RCBs strengthened using powder actuated fasteners achieved 65-70% of the increase in capacity of the beams strengthened using the conventional bonding 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 using the bonded method.