The effectiveness of reinforced concrete repairs may be establishedin terms of their ability to restore the structural integrity of the reinforcedconcrete element and to protect the reinforcement from severe weatheringconditions.The technique of bonding steel plates usmg epoxy adhesives isrecognized as an effective and convenient method for repair andrehabilitation of existing reinforced concrete structures. However theproblems associated with the steel corrosion, handling due to excessive sizeand weight, undesirable formation of welds, partial composite action withthe surface concrete and deboding, lead to the need for alternativematerials, and further research in this field. The high strength to weightratio, resistance to electro-chemical corrosion, larger creep strain, goodfatigue strength, potential for. decreased installation costs and repairs due tolower weight in comparison with steel, non-magnetic and non-metallicproperties of carbon fib er reinforced polymer (CFRP) composites offer aviable alternative to bonding of steel plates. The emergence of high strengthepoxies has also enhanced the feasibility of using CFRP sheets and fabricfor repair and rehabilitation.The mam objective of this thesis is to give better and fullunderstanding of the flexure behaviour of rectangular reinforced concretepre-cracked beams strengthened with Carbon Fiber Reinforced Plastics(CFRP) sheets.The experimental program involved testing fourteen R.C. rectangularbeams. They were designed to fail in flexure and tested under flexure in( ii )