Localized corrosion induced damage monitoring of large-scale RC piles using acoustic emission technique in the marine environment

Abstract

An experimental study was conducted to apply the acoustic emission (AE) technique to monitor the corrosion process and cracking behavior in large-scale reinforced concrete (RC) pile specimens. In this study, the underwater and tidal zones of six RC piles were exposed to accelerated, localized corrosion in a simulated marine environment to reach 5%, 10% and 20% steel mass loss. The two piles with 20% steel mass loss together with another reference pile without corrosion were continuously monitored during the test via three attached AE sensors. Tidal action had a significant impact on the AE signals; accordingly, a novel amplitude-duration-peak frequency-based AE signal filter (ADPF) was proposed, which achieved better performance than the previous amplitude-duration-based filters. Additionally, the conjoint analysis of AE signals and the fractal dimension of cover cracks throughout the corrosion period enabled global detection of localized corrosion-induced damage of piles, regardless of sensor location. This study also presents an integrated corrosion-induced damage detection framework and four models based on multi-layer perception (MLP) networks to predict the corrosion level of the underwater and tidal zones of piles in the marine environment.