International Concrete Abstracts Portal

Title: Use of Electrical Impedance Spectroscopy and Conductive Surface Films to Detect Cracking and Damage in Cement Based Materials

Author(s): Mohammad Pour-Ghaz, Mark Niemuth and Jason Weiss

Publication: Special Publication

Volume: 292

Issue:

Appears on pages(s): 1-16

Keywords: Acoustic emission, Conductive thin film, Crack detection, Damage detection, Electrical impedance spectroscopy, Frequency Selective Circuit, Ring test, Sensor, Structural health monitoring.

Date: 10/2/2013

Abstract:
This paper describes three electrically-based methods of damage detection in concrete materials. The first approach describes the use of EIS as an electrical sensing method for concrete. The results indicate that the electrical impedance spectroscopy of concrete can be used to detect cracks in concrete materials. Furthermore, this method can be used to obtain information on the geometry of the crack such as crack width and crack depth, however, the measurement are sensitive to the materials inside the crack. The second approach is the use of electrically conductive thin film that is applied to the surface of the concrete. The electrical resistance of this film increases due to cracking of the film and substrate. By monitoring the electrical resistance of this thin film, information about the time and location of cracking can be obtained. To evaluate the feasibility of using this method, it was used to detect cracking in restrained concrete elements while cracking was monitored with acoustic emission and strain measurements. The third approach presented in this paper describes the development and use of frequency selective circuit. A frequency selective circuit (FSC) has been developed to rapidly and simultaneously interrogate the response of multiple conductive surface elements. The response of the FSC is analyzed using numerical methods and the use of the FSC is demonstrated using a pilot study in which conductive films were used to simultaneously monitor the time of cracking of multiple restrained concrete rings.