Research on in-situ corrosion process monitoring and evaluation of reinforced concrete via ultrasonic guided waves

•Ultrasonic guided waves is performed to capture the initial and cover cracking stage of reinforced concrete.•A similar pattern that the minimum value amplitude can identify the initial cracking while the maximum one can represent the cover cracking.•Effects of three parameters (steel type, water-to-cement ratio, and concrete cover thickness) on the corrosion process can be identified via amplitude variation. A simply strategy for monitoring the corrosion process via the peak-to-peak amplitude of ultrasonic guided waves is performed to capture the initial and cover cracking stage of reinforced concrete. In this study, the accelerated corrosion process of steel in concrete is traced, and three factors (steel type, water-to-cement ratio, and concrete cover thickness) are investigated and analyzed. The results show that the amplitude variation can obey a similar pattern that the minimum value (valley) can identify the initial cracking while the maximum value (peak) can represent the cover cracking condition. Moreover, the steel type shows little effect on the amplitude value, but the higher water-to-cement ratio and the thicker concrete cover thickness can significantly decrease the amplitude value in each monitoring period. This study indicates the potential application of the ultrasonic guided waves amplitude for monitoring the corrosion process.