Natural disasters such as earthquakes, hurricanes, tornadoes, and tsunamis, as well as human vandalism due to wars and terrorist attacks can damage or destroy deficient structures in a matter of seconds. As a result, various strengthening techniques have been developed. Traditional strengthening and retrofitting techniques include concrete and steel jacketing are time consuming and labor intensive and do not always provide the most appropriate solutions. The bonding of thin fiber-reinforced plastics (FRP) composites on the surface of concrete members has emerged as an effective method to increase both the strength and stiffness of concrete members. Fiber reinforced polymer (FRP) composites have been extensively investigated for strengthening, due to its superior performance. Although a large volume of experimental research have been carried out and studies have been made during the past four decades to realize the performance of composite materials as strengthening/retrofitting for existing concrete structures to increase their load carrying capacity, there appears to be less work reported on studying the repair and rehabilitation of damaged structures. The present study is conducted to examine the efficiency of external FRP strengthening systems for repair and rehabilitation of damaged concrete columns using different CFRP/GFRP composites. Several sets of concrete column specimens with different water cement ratios had been implemented and tested by subjecting them to compressive strength tests till failed, and then repaired using the epoxy paste material and strengthened with either CFRP or GFRP strengthening composites and subjected to the compressive strength test again till failure occurred. The results showed that a significant improvement in compressive strength of repaired specimens.