In this paper, an experimental study is presented on a wide variety of fresh and hardened characteristics of an optimized steel fiber-reinforced self-compacting concrete (SFRSCC) mix. This is in order to examine the possibility of using this type of concrete to strengthen a corroded RC concrete beam with dimensions of 150×200×1200 mm. Micro steel fibers MSF were utilized at percentages of 0, 0.25, 0.5, 0.75, and 1% by volume. Using multi-objective optimization approach SFRSCC mix is optimized based on multi responses (tested properties). The theoretical optimization and its verification based on testing different fresh properties (slump flow, T500, L-box and segregation resistance), mechanical properties (compressive, flexural, splitting tensile strength, and modulus of elasticity), in addition to related durability properties (porosity and water absorption). In this investigation, the results of the experiments indicated that steel fibers enhanced the compressive, flexural, tensile strength, and elastic modulus as well as sieve segregation test by 22.9, 77.9, 112.8, 18.3, and 55.6% respectively which was achieved using 1% percentage of steel fiber. However, the rest of the properties are negatively affected due to the rise in fiber content. Thus, it was decided to implement a multi objective optimization process to get the optimum content. The optimum SCC mixture that satisfies all requirements was found using statistical software (Minitab 2018). The theoretical chosen optimal ratio of 0.47% of fibers that was obtained through optimization and it was evaluated and empirically verified. The optimal ratio was used in SCC mix for strengthening purposes with 30 mm jacket thickness for corroded RC beam. Strengthen corroded RC beam showed a considerable increase in its bending capacity, around 20%, contrasted to the corroded beam. The utilization of this method of strengthening also increased the ultimate load at first crack and the stiffness. Thus, it can be deduced that the method used is an effective method of strengthening.
