Evaluation of Nondestructive Test Methods for Concrete Bridge Deck Condition Assessment

Abstract

To facilitate locating subsurface concrete bridge deck defects and determining their corresponding severity, departments of transportation are switching to nondestructive test (NDT) methods. However, the difficulty in consistently locating defects with any one method has inspired investigations of the accuracy of each NDT method in detecting different defects. Accordingly, this project aims to assess the accuracy of nondestructive technologies available to the Alabama Department of Transportation (ALDOT) to evaluate the in-place condition of concrete bridge decks. To accomplish this, 20 laboratory specimens and an 18 ft by 31 ft bridge were fabricated with simulated defects representative of those found in a typical in-service deteriorated bridge decks. Ground-penetrating radar, impact-echo, infrared thermography, half-cell corrosion potential, and electrical resistivity technologies were used to locate delaminations, corrosion, deterioration, voids, cracks, and poorly constructed concrete. Recommendations for the use of each NDT method in identifying different concrete subsurface defects were developed.