DETECTING THE DEFECTS

Remote sensing infrared thermography, which can locate voids before structural failure, is an important tool in preventive maintenance. The high resolution, custom designed infrared thermographic scanning systems can be used to measure thousands of surface temperatures simultaneously in real time. The resulting data is displayed as computer images with areas of differing temperatures, designated either by differing gray tones on a black and white image or by various colors in a color image. The use of infrared thermography to perform an inspection of a concrete and asphalt overlaid deck on a bridge in the Mississippi River in St Louis is described. The use of an infrared scanner system utilizing temperature differentials caused by a sewer void to produce a picture of that void from above ground without boring is also described. Since emergency repairs cost more than preventive maintenance, indentifying sewer problems before a cave-in can be crucial