By D. S. Prakash Rao The University of the West Indies, Trinidad and Tobago
Bridges are high investment structures, and important land marks in any country besides being vital links in transportation systems. Assessing the quality of construction for structural safety is expensive and time consuming. Infrared thermography, on the other hand, provides a fast method of scanning large areas effectively. An assessment of the safety and quality of construction of a concrete bridge is presented. The investigations were later extended to a few other concrete bridges. The quality of construction of the bridges was assessed using infrared thermography for the first time in India. Infrared thermography was adopted among several other methods of non-destructive testing, and was found to be fast and effective in locating zones of deficient concrete in the structures. The images of the structures taken on different days during various times of the day were assessed for deficiencies. The suspect regions indicated by thermal images were confirmed by other techniques, and remedial programs were designed to correct the quality of concrete. The effectiveness of thermal images in the assessment of bridge structures, confirmatory tests, and remedial measures are described in this brief paper.