his research studied the behavior of reinforced concrete columns strengthened by jacketing with selfcompacting concrete using different types of aggregates. The study, based on experimental results of twenty columns (150X150 mm and 700mm height), strengthened with 50mm thick jacket. The samples are distributed as follows: Two samples are used as a reference without strengthening to determine the failure load of columns. Nine samples of gravel columns classified into three groups strengthened using jacketing techniques of gravel, dolomite and basalt respectively, each group consists of three columns, the first one has no treatment, the second one treated by epoxy and the third one treated by epoxy and dowels. Nine samples of dolomite columns with the same classification of gravel samples as mentioned above. The results reveal observed behavior, ultimate load-vertical displacement curves, the failure modes and the effect of variables on measured values, comparisons of the experimental results and the crack formation was influenced by both the jacketing type and the concrete agent.