Reinforcement Corrosion Monitoring of Reinforced Concrete Structures Using Piezoceramic-based Wave Method

摘要

Reinforced concrete (RC) structure is the most widely used type ofstructure, and their durability can never be ignored. Reinforcementcorrosion in RC structures is one of the most important factors leadingto premature failures of the structures. The reinforcement interfacialcorrosion of RC structures in high corrosion environment is easilyinduced in offshore engineering and the reinforcement corrosionmonitoring (RCM) research is of great significance. In this paper, theissue of RCMs in offshore RC structures is studied by means oftheoretical analysis, indoor test and numerical simulation, aiming atproposing a novel RCM method for offshore RC structures based onLead Piezoelectric Zirconate Titanate (PZT) wave method. Theproposed method can not only reveal the influencing law for thereinforcement corrosion level and concrete cover on the PZT-basedwave propagation behaviors, but also can quantitatively characterize thereinforcement corrosion thickness. For the purpose, the frequencydispersion and energy attenuation characteristics of guided ultrasonicwaves (GUWs) in corroded steel bars is first studied. Then, thequantitative relation between parameters such as corrosion level andsignal characteristics is investigated and established by finite elementmethod (FEM). Finally, through an electrochemical corrosionmonitoring test, the reinforcement corrosion process is monitored, thecorrosion affecting factors that induce the change of the GUWpropagation properties are extracted, and a damage detection index andthe corresponding evaluation method based on the GUW energy changeare proposed. The results show that the uniform corrosion of thereinforcement in RC structures is revealed to a certain extent, the GUWenergy is captured by PZT sensors, and the longer corrosion time resultsin the more serious corrosion damage and the smaller echo sensingsignal energy.