Effect of self-healing of cracks in chloride ion diffusion and corrosion of engineered cementitious composites

This study investigates the chloride penetration resistance and electrochemical behavior of self-healing engineered cementitious composites (ECC). The experimental program involved exposing cracked ECC samples to NaCl solution, while monitoring chloride penetration and self-healing using water-permeability tests. Electrochemical measurements, including open circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy, were used to evaluate reinforcement corrosion over a 91-day period. Results show that water-tightness does not guarantee protection against chloride ingress, as cracks with widths exceeding 0.15 mm allowed chloride penetration despite self-healing. Reinforcement depassivation occurred within 1 to 3 days of chloride exposure, but self-healing reduced the corrosion current back to pre-crack levels within 1 to 2 months, highlighting its role in delaying corrosion propagation. These findings emphasize the importance of crack width control in achieving effective self-healing and suggest that electrochemical impedance spectroscopy is a useful technique for monitoring the self-healing process in reinforced ECC structures. • Self-healing ECC showed varying resistance to chloride ion penetration. • Water-tightness doesn't always prevent chloride ingress in cracked samples. • Cracks smaller than 0.15 mm showed improved chloride penetration resistance. • Self-healing reduced corrosion current to pre-crack levels within 1 to 2 months. • EIS measurements effectively monitored changes during cracking and self-healing.