Vibrational energy harvesting in micro-electro-mechanical systems integrated with sacrificial anode metal sheets for detecting steel corrosion in concrete

^1,2,3 Environmental Material Engineering Laboratory, Faculty of Engineering, Hokkaido University, Hokkaido, Japan
^4,5,6 R&D Center, Saginomiya Seisakusho, Inc., Sayama, Saitama, Japan

Abstract

Reinforced concrete (RC) structures in marine environments are highly susceptible to deterioration caused by chloride-induced corrosion of reinforcing steel bars. Although substantial resources are often allocated for maintenance, developing more efficient systems for monitoring RC structures in corrosive conditions is essential to ensure their long-term durability and safety. This research aims to establish a clear connection between the surrounding corrosion environment and the behaviour of steel bars embedded in concrete, which is vital for maintaining the required service level of RC structures. Sacrificial Anode Metal Sheets (SAMS), integrated with a Micro Energy Harvester (MEH) based on Micro-Electro-Mechanical Systems (MEMS) technology, are proposed and employed to continuously monitor the environmental conditions affecting the degradation of the targeted structure. The sensor detects the frequency shift of vibrational behaviour in real-time, providing critical information on corrosion progress of steel bars in concrete. To modify the monitoring accuracy, Half-Cell Potential (HCP) measurement for rebars in concrete is conducted to correlate the corrosion of SAMS with the steel bars inside the concrete. Frequency changes detected by MEMS-SAMS strongly correlate to HCP data, confirming that MEMS-SAMS can effectively monitor the corrosion due to chloride attack. This relationship significantly enhances early detection and optimizes maintenance strategies for RC structures in highly corrosive environments.