At the site rehabilitation or upgrading of reinforced concrete members using enlargement of the cross section, bonded steel plates was an effective, convenient, and economic method of improving structural performance. However, disadvantages inherent in the use of steel or traditional enlargement of concrete element, where possible, have stimulated research into the possibility of using fibre reinforced polymer (FRP) materials in its place, providing a non-corrosive, more versatile strengthening system. The need for repair and strengthening may arise from deterioration, changes in use, changes in the relevant design codes, structural defects, or seismic conditions.