Determination of the applicability and limits of void and delamination detection in concrete structures using infrared thermography

Based on the results of the infrared thermography of 51 artificially created defects - voids and delaminations - in concrete, it was shown that it is possible to detect defects at depths that are equal or less than the defect size D using the thermal contrast method. By applying the phase contrast method, an increase of 50% in the maximum depth for a given defect size D was achieved. Delaminations containing thin air gaps were detected with the same success as much larger voids of the same cross section. (C) 2015 Elsevier Ltd. All rights reserved.