Repair effect of bidirectional electromigration rehabilitation on concrete structures at different durability deterioration stages

Abstract Bidirectional electromigration rehabilitation (BIEM) technology is a novel method to improve the durability of existing reinforced concrete structures. BIEM repair effects are proportional to operation time, which is applied during the process of different durability degradation of concrete structures. In this paper, three different durability deterioration stages (passivation, depassivation, and corrosion) were prepared for BIEM repair effects research. BIEM repair effects were evaluated using polarization curve, chlorine removal efficiency, amount of corrosion inhibition, and steel bars corrosion profile. Short-term effects indicated that BIEM efficiently removed chloride ions and changed the steel bar microenvironment to prevent its corrosion. This effect was especially apparent for low-corrosion situations. Long-term effects showed that BIEM extended the passivation time to ten dry-wet cycles for low-corrosion specimens. However, BIEM treatment did not prevent corrosion once the initial corrosion surpassed a certain threshold. Corrosion ratio is an important factor that influences the BIEM repair effects for a given corrosion stage. Based on the long-term effects results, repair strategies for non-corrosion and corrosion stages concrete were discussed.