Many techniques have been used in repair and strengthening of reinforced beam, among which are external steel beams, external pre- stressing, epoxy injection, additional concrete overlay, external steel plates, additional longitudinal and transverse - steel bars. Fifteen R.C. beams were tested until failure and the deflection, surface strains, internal steel strains, external steel strains and crack patterns were measured, the results were analyzed and conclusions were summarized. Finally, the recommendations were stated with the needed future work.