Nondestructive debonding detection of fiber reinforced plastics strengthened structure based on infrared thermal imaging with laser thermal excitation

Abstract

The infrared thermal imaging detection technology is often utilized for the debonding detection of concrete reinforced by fiber reinforced plastics (FRP) sheets. However, the traditional heat source excitation infrared thermal imaging method is affected by factors such as short heating distance, low thermal sensitivity and high power consumption. In order to solve these problems, the debonding detection of FRP-reinforced concrete structures based on optical excitation line laser heat source infrared thermal imaging method was proposed to detect the debonding of FRP reinforced concrete. The surface local heat distribution anomalies caused by debonding in the structure could be measured by an infrared camera. Based on the numerical and experimental results, it is proved that the method has the advantages of debonding detection in FRP reinforcement structure: (1) the feasibility of using laser scanning thermal imaging technology to detect the debonding damage in FRP modified concrete structure; (2) FRP reinforcement long-distance, high thermal sensitivity and low power consumption damage detection of concrete structures.