Estimation of Delamination Depth in Concrete by Passive Thermography Using Inverse Analysis

Abstract

Passive infrared thermography is an effective technique for detecting delamination in concrete structures. However, the method is dependent on weather conditions, when solar radiation is used. This research investigates the possibility of quantitative estimation of delamination depth in concrete by using the passive infrared thermography under solar radiation. An inverse approach is introduced for the quantitative estimation from transient temperature distribution on concrete surface under various weather conditions. In the inverse method the time series thermographs of observed surface are compared with those obtained by the FEM analyses. The inverse analysis is applied to experimental data obtained by infrared camera. It is found that delamination depth can be quantitatively estimated by using the inverse analysis.