Infrared Thermography (IT) is a technique used for locating shallow delaminations, cracks, and voids in concrete and other pavements as well as air gaps and voids within concrete slabs, block walls, and other structures. Infrared Thermography senses the emission of thermal radiation from a member and can be used to produce a 2D image from the thermal signal. It is based on two basic principles from heat transfer: conduction and radiation. Sound concrete with no voids, gaps, or cracks is more thermally conductive than low density or delaminated concrete, which then creates small temperature differences on the concrete surface. These temperature differences can be detected and mapped by the sensitive Infrared Thermography equipment. This allows rapid areal mapping of internal conditions. It should be noted that the IT method is most useful for the detection of shallow defects and flaws. Flaws deeper in a structure produce smaller and more diffuse thermal effects at the surface.