A Nondestructive Testing Method for Crack in Carbon Fiber Reinforced Concrete with Infrared Thermography

Abstract

Based on the functional characteristics of carbon fiber reinforced concrete (CFRC), an improved infrared nondestructive testing method, to detect crack in CFRC by using infrared thermography, is presented in this paper. The principle is that when a CFRC specimen is applied a low voltage, crack existing in the specimen will result in non-homogeneous surface temperature distribution due to the electro-thermal effect of the material. Monitoring the temperature difference on the surface, the crack under the observed surface can be inspected by using infrared thermography. In theory, the mechanism causing the temperature difference comes down to an unsteady heat transfer problem with internal energy sources. In the case of the thermo-physical property of CFRC as given, the sensitivity of this method to the depth of the crack is analyzed by numerical computation.

Review and comparison of shearography and active thermography for nondestructive evaluation

“…Currently, visual and hammer tapping are the most widely used in-situ method for inspection of FRP laminates [67], with other techniques also being developed for this purpose, such as ultrasonic [69][70], acoustic emission [71][72], near-field microwave [67] and infrared thermography [73][74]. Shearography, which had been applied successfully for detecting composite delamination in aerospace and automotive industry [21,36,51,75], could be easily adapted to similar civil engineering applications.…”