Attenuation-Based Methodology for Condition Assessment of Concrete Bridge Decks Using GPR

Reflection amplitude at top rebar layer has been used as a main criterion for evaluating attenuation of ground-penetrating radar (GPR) data from concrete bridge decks. However, a recent study has pointed out the limitation of this practice. Motivated by that same research, the current paper presents a robust method for performing GPR attenuation analysis. Also based on correlation between A-scans, however, instead of baseline data, semi-simulated waveforms are used in this approach. with only one reflection representing direct coupling, these waveforms mimic A-scans collected from completely damaged location. The output obtained is then plotted in form of a contour map of correlation coefficient in which higher value indicates more deteriorated concrete. As a validation, the method was implemented for two bare concrete bridge decks. The result indicates that while the maps provided by other technologies and GPR are geometrically correlated, in comparison with conventional amplitude analysis, the proposed model provides better vision on overall deterioration of bridge decks.