ConcrEITS: An Electrical Impedance Interrogator for Concrete Damage Detection Using Self-Sensing Repairs

Area of Science:

• Civil Engineering
• Materials Science
• Electrical Engineering

Background:

• Continuous monitoring of concrete infrastructure is crucial for timely detection of damage and repair failures.
• Alkali-activated materials offer potential for concrete repair and embedded sensing, but damage detection via self-sensing repairs remains undemonstrated.
• Existing commercial interrogation solutions for damage detection are prohibitively expensive.

Purpose of the Study:

• To design and demonstrate a low-cost tomographic impedance interrogator for crack detection in concrete using conductive repair patches.
• To evaluate the accuracy and capability of the developed system compared to commercial devices.
• To assess the system's effectiveness in locating cracks in concrete structures under stress.

Main Methods:

• Development of a low-cost tomographic impedance interrogator named "ConcrEITS".
• Validation of 4-probe impedance measurements against a commercial device using pure material blocks.
• Tomographic reconstruction and crack location analysis on concrete beams with conductive repair patches undergoing 4-point bending.

Main Results:

• ConcrEITS achieved a root mean square error of ±5.4% for 4-probe impedance measurements compared to a commercial device.
• The system successfully detected and located cracks in conductive repair patches on concrete beams.
• Tomographic reconstruction clearly identified crack locations in all six tested samples.

Conclusions:

• The developed ConcrEITS system shows significant promise as a cost-effective solution for combined monitoring and maintenance of concrete infrastructure.
• The technology demonstrates the feasibility of using self-sensing repair patches for damage detection.
• Further up-scaled testing is recommended before field trials to validate the system's performance in real-world applications.