Nondestructive Evaluation of Bridges

Civil structures, including buildings and bridges, have not been given high priority for application of advanced nondestructive evaluation (NDE) techniques as compared with aircraft and aerospace structures. Although in recent years there has been an increase in nondestructive techniques for construction materials such as concrete and wood, the funding for these techniques is miniscule compared with that spent on advanced materials for military applications. In fact visual inspection once every two years is the primary technique used for routine inspection of bridges, and buildings have been given even less attention. Conventional nondestructive testing (NDT) is only used as an adjunct to visual inspection and very few advanced nondestructive evaluation (NDE) techniques are used at all. This paper will present an overview of the current nondestructive methods used for inspection of civil structures. Examples will be given of developments over the recent past which have resulted in improvements in nondestructive inspection of civil structures and techniques. Also to be discussed are those methods used in other applications and those emerging from research laboratories, which afford the potential to greatly improve NDE techniques for inspecting civil structures.