Resonant Eddy Current Sensor Design for Corrosion Detection of Reinforcing Steel

Area of Science:

• Materials Science
• Civil Engineering
• Electrical Engineering

Background:

• Corrosion in reinforced concrete (rebar) structures poses significant risks to structural integrity.
• Existing eddy current (EC) sensors face limitations in detection range and sensitivity for embedded rebar.
• Accurate, non-destructive methods are needed to assess rebar condition within concrete.

Purpose of the Study:

• To develop and evaluate an LC resonator-based single-frequency EC sensor for detecting rebar corrosion.
• To achieve a detection range of 5-6 cm from concrete and differentiate corrosion levels.
• To address the challenges of limited range and sensitivity in current EC sensing technologies.

Main Methods:

• Systematic experimental selection of LC resonator parameters.
• Characterization of inductor parallel resistance (Rp) as a corrosion indicator.
• Evaluation of sensor performance with simulated rebar corrosion in concrete.

Main Results:

• Identified parallel resistance (Rp) as a key parameter for rebar corrosion assessment.
• Quantified temperature dependency of Rp (approx. 155 Ω/°C) for potential compensation.
• Achieved detection accuracy of approximately 0.17 mm material loss in simulated rebar corrosion.

Conclusions:

• The developed EC sensor effectively detects rebar corrosion in concrete structures.
• The sensor offers a promising non-destructive evaluation tool for assessing rebar condition at a distance.
• The findings contribute to enhanced structural health monitoring and maintenance strategies.