Rehabilitation and strengthening for shear of RC beams using CFRP and GFRP

The use of Fiber Reinforced Polymers FRP in repair and rehabilitation of reinforced concrete structures is gaining worldwide acceptance due to their numerous advantages of FRP over other repair materials. In this paper, the structural behavior of reinforced concrete beams repaired using Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) fabrics, was investigated. Five beams of 100x300x1100 mm designed to assure shear failure, were cast, cured and then loaded to failure. Ultimate load, load- deflection relation and crack pattern were recorded for each beam. Beams were then repaired using either CFRP or GFRP. Wraps were epoxy bonded on both sides of beams, except for one beam where the bottom was also wrapped for comparison. Damaged and subsequently repaired beams were then loaded to failure. Ultimate load and ductility were compared.It was concluded that the use of either GFRP or CFRP wraps restores and improves both the load carrying capacity and the ductility of tested beams. GFRP repaired beams demonstrated better results than the CFRP repaired ones. The beam repaired on both sides and bottom showed better load carrying capacity than those where wraps were applied on sides only. Failure of rehabilitated beams was found to be due to debonding and peeling of FRP wraps. The repair method was found to be easy, efficient and less time consuming compared to other conventional repair methods