Influence mechanism of crack width and location on the efficiency and effect of electrophoretic deposition repair of rust-cracked reinforced concrete

Reinforced concrete structures are prone to rust expansion cracking during service. Electrophoretic deposition repair is one of the effective coping technologies, but in actual engineering, the width and location of rust expansion cracks are not fixed, which affects the repair efficiency. This study was conducted by controlling the crack width and location variables. The results show that an increase in crack width reduces the inter-electrode resistance, expands the effective action area of the electric field, enhances the electrophoretic deposition rate of the repaired molecules, and increases the improvement amplitude of the waterproof performance of the specimens. For every 0.1 mm increase in width, the molecular deposition rate increases by 7 %. By comparing the repair of cracks in different locations, the lower crack achieved a filling rate of 92 % due to the synergy of electric field force and gravity, and the density of the epoxy resin film was the best. The lateral crack cause the deposition path to shift downward due to gravity, presenting an asymmetric filling (filling rate of 73 %). The upper crack needs to overcome the gravity barrier, and the filling rate in the middle drops to 57 %. The research provides a theoretical basis for the optimization of specific crack repair parameters. • Rust-induced crack widening reduces inter-electrode resistance, expands electric field action range, and accelerates electrophoretic deposition of repair molecules. • When the gravitational force and the electric field force are in the same direction, the repair rate and filling density of rust-induced cracks are the highest. • The electric field intensity and the angle of the anode plate should be adapted to the width and position of the rust-induced cracks to achieve efficient repair.