Feasibility of Infrared Thermography for Bridge Deck Inspection Without Lane Closure and the Uncertainties - Preliminary Report -

Aging and deterioration of bridges are becoming serious problems worldwide. Non-Destructive Evaluation (NDE) methods, such as Infrared (IR) and High Definition (HD) cameras, have been developing for high-speed inspection without any lane closures to quantify rapid deterioration progress due to the aging of bridges and increase of maintenance budget. However, accuracy and reliability of bridge deck condition evaluation by IR Thermography (IRT) at highway speed is still insufficient. In this study, IR images of a bridge deck in service were taken while driving with three different types of IR cameras, and the results were compared with other NDE methods conducted by other researchers at the same bridge. The results proved that IRT with a cooled camera has a possibility to perform damage detection for concrete bridge decks with certain accuracy and reliability even if it is utilized while driving at highway speed without lane closure, and the performance level is almost similar to other NDE methods under static situation. In terms of application of IRT with an uncooled camera for high speed inspection, it showed relatively larger area of damage indications and higher False Positive misdetection ratio. Since the number of core samples and the area of test field were very limited, more research is required to further evaluate the conclusions of this paper. This paper shows preliminary results, and more detail will be reported in subsequent publications.