The width of cracks has a significant impact on chloride ion transport and the corrosion of steel in concrete. This study employed a constant-voltage accelerated corrosion test, electrochemical impedance spectroscopy, and chloride penetration measurements, to investigate the evolution of steel corrosion and chloride transport in cracked concrete. Results show that crack widths of 0.1-0.3 mm strongly affect both the electrochemical behavior of steel and chloride ion transport. The corrosion potential of all specimens gradually shifted in the negative direction over time. In specimens with crack widths of 0.3 mm and 0.5 mm, the initial corrosion potential was lower than -0.126 V. However, the time required to reach a corrosion current density of 0.1 μA/cm2 ranged from 88 h to 214 h. As exposure time increased, the Nyquist plots displayed distinct capacitive arcs, and the minimum absolute value of the maximum phase angle in the Bode plots reached 6°. The maximum chloride penetration depth was 30 mm.
Wang et al. (Sun,) studied this question.