The applicability of infrared thermography in the detection of delamination in bridge decks

The use of infrared thermography to very accurately define variations in surface temperatures was evaluated as a means of identifying delaminated areas caused by corrosion of reinforcing steel in concrete bridge decks. It was found that because of the vast differences in the volumetric heats of the solid concrete and the air in the cracks around a delaminated area, the separated concrete was warmer when exposed to solar heating than was the adjacent sound material. Differences in the temperatures of the deck surface, shown in various shades or colors on a cathode ray tube, were photographed to provide a permanent graphic record of the location of the warmer, distressed areas.