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Title |
Evaluation of Corrosion Environment in Reinforced Concrete through Electrochemical Impedance Spectroscopy (EIS) Using Surface-Mount Electrochemical Sensors
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Authors |
응웬 후 바오 안(Ngan H. B. Nguyen) ; 이성진(Sung Jin Lee) ; 김제경(Je-Kyoung Kim) ; 이정재(Jurng-Jae Yee) ; 기성훈(Seong-Hoon Kee) |
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DOI |
https://doi.org/10.4334/JKCI.2025.37.4.435 |
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Keywords |
콘크리트; 철근부식; 부식환경; 전기화학적 센서; 교류임피던스 concrete; steel corrosion; corrosion environment; electrochemical sensor; AC impedance |
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Abstract |
This study developed a surface-mounted miniature electrochemical impedance spectroscopy (EIS) sensor to evaluate the corrosion environment of reinforcing steel in concrete and validated its performance through comparison with existing commercial sensors. The developed sensor features a compact design that integrates both the reference electrode (RE) and the counter electrode(CE) into a single structure. It demonstrated performance comparable to that of commercial sensors under various saline conditions. Specifically, the standard potential of the developed sensor was measured to be approximately +292 mV relative to the silver/silver chloride (Ag/AgCl) electrode. It was confirmed that a correction of about +24 mV is required for assessing corrosion risk based on ASTM C876 standards. The AC impedance analysis revealed that the developed sensor effectively monitors changes in the electrical properties of concrete surfaces. By analyzing impedance signals, the solution resistance (Rs) was measured to assess the drying state of the concrete, and the analysis of capacitance (Cdl,0 and Cdl,1) values, as defined by the electrochemical equivalent circuit, provided information on saline concentrations. These findings support the utility of the developed sensor in quantitatively identifying changes in the electrochemical properties and environmental conditions of reinforced concrete structures. The surface- mounted EIS sensor proposed in this study demonstrates significant potential as a practical and non-destructive tool for corrosion monitoring in field applications.
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