Multi-Phase Bridge Deck Evaluations Using Aerial and Vehicle-Based Testing
In early autumn of 2020, Infrasense headed to the Hoosier state to perform multi-phase condition surveys on 71 bridges decks. A suite of nondestructive testing technologies were deployed across four groups of bridge decks that were selected using different sets of objectives. The broadest level of testing was performed on 43 bridge decks using aerial infrared thermography (IR) to map delamination. Aerial IR offers a variety of advantages over traditional bridge deck inspection methods such as sounding and coring. Condition data for hundreds of bridge decks can be collected in a single day with no exposure of inspection crews to traffic and no lane closures or traffic disruptions. Various studies comparing vehicle-based infrared data with fixed-wing aerial infrared data have demonstrated that the aerial IR system provides adequate resolution to detect delaminations and evaluate overall deck condition. These efficiencies result in more data at a much lower cost per deck, making aerial IR one of the most economical means of network-level bridge deck evaluation.
A network of 20 bridges were tested in greater detail using a vehicle-based system of air-coupled ground penetrating radar (GPR) and IR operated at normal driving speeds. At the most detailed project level, a group of 10 decks were tested in two phases; the vehicle-based GPR and IR system was deployed for phase 1, and more detailed ground-coupled GPR and confirmative impact echo testing was performed in phase 2 using temporary lane closures. Finally, a group of 10 newly constructed decks were scanned using only air-launched GPR in order to evaluate condition and rebar depth.
This project illustrates the range of services and expertise that Infrasense can provide. Our team has experience working with repeat customers who have incorporated nondestructive evaluation into their asset management programs, as well as new clients who are interested in learning how these testing techniques can help them make better use of their maintenance budgets. Whether it is evaluating hundreds of bridge decks using aerial IR or working in a lane closure to collect high resolution data for scoping repair quantities and locations, Infrasense is able to provide our clients with high quality results that meets their needs.