Quantifying Bridge Deck Corrosion Using Ground Penetrating Radar

Current visual bridge deck inspection techniques do not provide enough quantitative information about the deck’s deterioration state to support maintenance and rehabilitation decisions. In recent years, ground penetrating radar (GPR) has shown promise in the ability to determine deterioration quantities, with data that can be collected quickly on multiple decks without lane closures. The work presented in this article seeks to develop a method to relate GPR analysis results to the level of active corrosion in a bridge deck. By multiplying the mean and skewness of the rebar reflection amplitudes of a variety of bridge decks, and comparing these values to corrosion quantities based on half-cell potential (HCP) measurements, a master curve with a correlation coefficient of 93% was developed. This article also presents a step-by-step procedure for developing an amplitude threshold for future deck assessments using GPR alone.