Concrete Pavement Service Condition Assessment Using Infrared Thermography

Infrared thermography (IRT), an effective nondestructive testing method, is used to obtain an initial evaluation of the concrete pavement surface and near surface in a time effective manner. In this paper, the effect of the depth of delamination inside concrete pavement on infrared thermography technique is studied for bridge decks inspection. To be able to mimic the delamination in subsurface, two Styrofoam cubes have been inserted in different depth near the surface of the concrete cylinder. After heating up the specimen, thermal images were taken from the surface using an infrared thermal camera to evaluate the effect of subsurface defects on detection sensitivity and accuracy. We also investigated the precision to which the shape and the size of the subsurface anomalies can be perceived using an uncooled thermal camera. To achieve this goal, we used image processing technique to accurately compute the size of delamination in order to compare it with the actual size. In addition, distance/thermal graph is used to detect the presence of the defect underneath the concrete surface. Furthermore, thermal transfer modeling was adopted in this paper to assist the setup of this experiment and the results are compared with laboratory findings.