Inside Story: Recent Developments in NDT Technologies

This article looks at key areas of non-destructive testing (NDT) technology that have experienced significant improvement over the last several years. The author reviews the current state of NDT methods in the bridge industry, where such technologies were once considered to be risky. NDT techniques have now become standard in bridge assessment. The author notes that the achievement of rapid coverage is a chief advantage of non-destructive methods over more conventionally intrusive methods. Some of the testing methods discussed include low frequency ultrasonics, used for concrete investigation; acoustics emissions, used to detect cracks, corrosion, and damaged cables; array radars (e.g., Hermes system) used to scan an entire road lane width to detect corrosion damage in concrete bridge decks.