Effect of electro-deposition on repair of cracks in reinforced concrete

•Focus was placed on effect of electro-deposition on microstructures of concrete.•Electro-deposition exerted negligible influences on mineral compositions of samples.•Electro-deposition improved overall compactness of samples. The electro-deposition technique can be used to repair cracks in reinforced concrete. Inevitably, this treatment affects the physical and chemical properties of the reinforced concrete. However, scant research has focused on the effect of electro-deposition on the microstructures of concrete. This study investigated the changes in the compositions and morphology of reinforced concrete with cracks after electro-deposition treatment. The results showed that the electro-deposition treatment exerted negligible influences on the mineral compositions of mortar specimens. However, the overall compactness of mortar was significantly improved with a reduction in the total porosity and refinement in the most probable pore size. Microstructure observation revealed that deposits, such as Mg (OH)2 and ZnO, were distributed and accumulated on the interface between aggregates and hardened cement paste, which contributed to the improvement in the overall compactness of the mortar samples.