" TRB's second Strategic Highway Research Program (SHRP 2) Report S2-R06A-RR-1: Nondestructive Testing to Identify Concrete Bridge Deck Deterioration identifies nondestructive testing technologies for detecting and characterizing common forms of deterioration in concrete bridge decks.The report also documents the validation of promising technologies, and grades and ranks the technologies based on results of the validations.The main product of this project will be an electronic repository for practitioners, known as the NDToolbox, which will provide information regarding recommended technologies for the detection of a particular deterioration. " -- publisher's description.

This research has examined the use of nondestructive techniques for concrete bridge deck condition assessments. The primary nondestructive testing/evaluation (NDT/NDE) technique utilized in this research was ground-coupled ground penetrating radar (GPR). The objectives of this research were to examine the utility of the nondestructive techniques in evaluating the condition of MoDOT bridge decks to enable faster, better, and more cost-effective bridge deck assessments, and to determine the accuracy of the information provided.

An objective view of the relative advantages and limitations of the nondestructive testing and evaluation methods that are currently used in the inspection of bridge decks is presented and discussed. The three main nondestructive testing technologies that were evaluated are impact-echo, ground penetrating radar, and infrared thermography. Nondestructive testing and evaluation procedures, including methodology and equipment to evaluate concrete bridge decks with asphalt overlays, are also presented and discussed. Current results indicate that a combination of ground penetrating radar and infrared thermography would provide the best methodology for evaluating the structural integrity, e.g., delaminations, of concrete bridge decks with overlays. Furthermore, current results also indicate that the impact-echo method shows promising future development towards the nondestructive evaluation of bridge superstructures.

"Infrared Thermography (IRT) is a promising Non-destructive Evaluation (NDE) technique that has been widely used in bridge deck inspection. It is a quick and easy alternative to provide preliminary information of possible defected areas in bridge decks. However, detection capabilities and sensitivity to environmental conditions and material properties impose some challenges for the application of IRT. In this study, the effect of varying concrete mixtures on passive IRT was investigated. Four different concrete mixtures, conventional, high-strength, self-consolidated and lightweight concrete, were included in the evaluation. Various defects with relatively small sizes and depths were simulated and planted in cast-in-place slabs. The casting and testing took place in the United Arab Emirates (UAE), which is considered a hot weather region. The defected specimens were imaged, and the images were compared to non-defected specimens to enhance the judgment on defect detection. Thermal conductivity of each mix was estimated using the Maxwell- Eucken 2-phase composite material model, and Rapid Chloride Penetration was tested and used as an indication of density. The slabs were imaged during the cooling cycle. Results indicated that mix variation had a significant effect on IRT. High strength concrete achieved the highest detection possibility among the mixes. Furthermore, results showed that the higher the density and thermal conductivity coefficient, the better the defect detection using IRT at ideal imaging conditions is. For the UAE, ambient conditions are favorable for passive IRT, as the results indicated minimal sensitivity to wind, relative humidity, and temperature as opposed to other locations in the world where passive IRT would not be applicable. Nevertheless, because of IRT limitations, it would be better employed as a health monitoring technique with baseline comparisons rather than an independent primary inspection NDT tool for bridges."--Abstract.

The state of Wyoming alone has 13.1 million square feet of bridge deck, and evaluation of those decks has become an important part of the Wyoming Department of Transportation's (WYDOT) management of bridge repairs. The authors believe that development and advancement of nondestructive evaluation methods over the past 25 years may provide a more efficient, standardized, and accurate method for evaluating bridge deck conditions compared with current practices. A study was performed on three bridge decks in Wyoming: the First Street Bridge in Casper, the Douglas I-25 Bridge, and the Remount I-80 Bridge. For each bridge, an investigation was done using standard WYDOT practices for chain dragging. In addition, the bridges were evaluated using impact echo, thermal imaging, and ground-penetrating radar (GPR) techniques. All three methods considered were successful, and the damage locations between the impact echo, thermal imaging, and GPR generally correlated well. Based on this study, a complete bridge deck evaluation should combine impact echo with GPR testing to provide the most accurate predictions of delamination and debonding in support of optimal maintenance decisions.