Strengthening of Initially Loaded Reinforced Concrete Beams Using FRP Plates

In this study, the reinforced concrete (RC) beams are initially loaded to 85% of the ultimate flexural capacity and subsequently repaired with FRP (fiber reinforced plastic) plates, bonded to the soffit of the beam. The plate thickness is varied to assess the premature failure initiated at the plate curtailment zone due to the high concentration of shear and peeling stresses. Different repair and anchoring schemes were conducted in an effort to eliminate such failures and insure ductile behavior. The results indicated that the flexural strength of the repaired beams is increased. The ductile behavior of the repaired beams is inversely proportional to the plate thickness. The use of an I-jacket plate provided a proper anchorage system and improved the ductility of beams repaired with plates of large thickness.