Research on the characterization of reinforced concrete corrosion based on nonlinear coda wave interferometry

Reinforced concrete (RC) structures constructed in harsh environments are prone to corrosion, inducing a shorter lifespan. It is particularly important to monitor the RC corrosion in order to eliminate safety hazards. A novel method based on the nonlinear coda wave interferometry (NCWI) technique is proposed in the paper for the characterization of corrosion in reinforced concrete (RC) structures. By establishing the RC rapid corrosion experimental system, the variations of coda wave eigenvalues (Delta v/v and Kd) with the amplitude of the pump wave in RC samples are studied. The results show that: Delta v/v exhibits a strong linear relationship with the pump wave amplitude, while Kd shows a quadratic correlation with the pump wave amplitude in the corroded sample; NCWI can distinguish the corroded and intact RC samples efficiently. This study is expected to contribute to the advancement of ultrasonic testing techniques and the monitoring of reinforced concrete (RC) corrosion.