"Integrated non-destructive techniques were utilized to assess the condition of a reinforced concrete bridge deck. There were two main objectives accomplished. The first objective was to assess the integrity of the reinforced concrete bridge deck using four non-destructive techniques, namely visual inspection, ground penetrating radar, portable seismic property analyzer-ultrasonic surface wave, and hammer sounding and chain drag. Visual inspection data were used to identify signs of deterioration on surface of the bridge deck such as cracking, concrete leaching, and reinforcement corrosion. Ground penetrating radar data were used to determine the relative condition of the bridge deck. However, due to the significant differences in depth of the embedded reinforcements, ground penetrating radar data were not useful in terms of assessing the overall condition of the bridge deck. Portable seismic property analyzer-ultrasonic surface wave data were used to determine the concrete quality of the bridge deck by estimating average Young's modulus (elastic modulus). Hammer sounding and chain drag data were used to identify non-delaminated and severe delaminated areas in the bridge deck. The second objective was to demonstrate the effect of temperature and moisture content changes on ground penetrating radar signal amplitude. Ground penetrating radar signal amplitude variations associated with different weather condition of temperature and moisture changes were evaluated. Ground penetrating radar signal amplitude was increasingly attenuated during low temperature and high moisture content. In contrast, ground penetrating radar signal amplitude was decreasingly attenuated during high temperature low moisture content"--Abstract, page iii.

As the nation's infrastructure continues to age, there is a need to effectively and economically monitor and inspect bridges. With the introduction of non-destructive testing technologies such as Ground Penetrating Radar (GPR) for condition assessment of bridge decks, states will be better equipped to inspect, assess, and prioritize transportation funding to maintain, preserve, and improve infrastructure. The objective of the research is to improve the condition assessment of bridge decks through the use of GPR which can increase the speed, effectiveness, and accuracy of inspections. The non-destructive evaluation technique provides information that can be used to identify the potential amount of internal deterioration of a concrete bridge deck that cannot be identified with a visual inspection. As in many other states, New Mexico currently uses the chain drag method in which the inspection of the deck condition is solely based on inspector's subjective interpretation of the sound produced by dragging a chain over the bridge deck. The use of GPR has the potential to greatly improve the quality of the inspections by collecting more reliable and less subjective information on the condition of bridge decks. Through the collection and analysis of data acquired from the GPR on a set of reinforced concrete decks, this research seeks to provide a better understanding of GPR technology, data acquisition, and training needs for adoption of GPR in bridge deck inspections in the state of New Mexico. With a better understanding of the technology, GPR can become and indispensable tool for more informed decisions for the allocation of funds for maintenance and improved asset management. This research improves implementation and provides effective economic methods to employ this technology to improve the inspection and maintenance of bridge infrastructure.

" 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.

Government reports and published research have flagged and brought to public attention the deteriorating condition of a large percentage of bridges in Canada and the United States. Inspection and rehabilitation programs are being implemented to monitor and maintain deteriorated bridge infrastructure. Current practices of bridge inspection and condition assessment rely heavily on visual inspection, limited basic testing such as hammer sounding and chain dragging, and the use of Non-Destructive Testing on ad-hoc basis. These methods suffer from several limitations including subjectivity and uncertainty of visual inspection process, as well as traffic disruption resulting from lane closure during inspection. This research aimed to study, evaluate, and experiment with the use of remote sensing technologies in bridge inspection to minimize drawbacks of current practice. To achieve this objective, two models are developed in this research. The first is a comparative study of remote sensing technologies for concrete bridge condition assessment that provides a systematic approach of selecting most suitable technologies for use in condition assessment. Seven remote sensing technologies are examined in this model. It recommends technologies to be implemented based on a set of flexible multi-attributed criteria. The model provides flexibility to select specific set of these criteria and to define their weights based on user preferences and project objectives. The second model proposes a hybrid system of remote sensing technologies to augment current practice in bridge inspection and eliminate some limitations such as minimizing traffic disruption while performing bridge inspection and enhancing inspection data analysis and visualization. The hybrid system integrates the use of thermal Infrared (IR) and Ground Penetrating Radar (GPR). These technologies have the ability of acquiring data from a distance which minimizes traffic disruption. Results obtained from IR and GPR are in the form of maps of the detected defects on the concrete bridge deck. These maps are used as input in ArcGIS for better representation, visualization, and reporting of the defects and their extents. The hybrid system was examined in a case study of a concrete bridge deck in the city of Laval, Montreal, Quebec, Canada. The results are compared to those obtained using hammer sound test for validation.