Missouri S&T Nondestructive Evaluation of Bridge Decks \u2013 Pilot Study: Bridge A2966

US Transportation Collection2014PDFImageSneed, LesleyAnderson, NeilTorgashov, EvgeniyMissouri University of Science and Technology. Department of Civil, Architectural, and Environmental EngineeringMissouri University of Science and Technology. Dept. of Geological Sciences and EngineeringUnited States. Department of Transportation. Federal Highway AdministrationMissouri. Dept. of Transportation. Research, Development and Technology DivisionMissouriBridge decksNondestructive testsConcrete bridgesGround penetrating radarEvaluationPortable equipmentData collectionStructural health monitoringcmr14-010TRyy1308Ground Penetrating Radar (GPR) image of Bridge A2966. 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.Eleven bridge decks were investigated using detailed visual inspections, GPR, portable seismic property analyzer (PSPA), core extraction, and chloride ion concentration measurements. The cores underwent a detailed visual evaluation and testing to determine the volume of permeable pore space. Data sets were compared to determine correlations between the results. Three of the bridge decks investigated underwent rehabilitation by hydrodemolition after the initial investigation, and concrete material removal was surveyed using lidar to evaluate the NDE estimations. Good correlation was observed qualitatively. Areas of the decks where the GPR interpretations indicated evidence of extensive deterioration generally corresponded to areas with greater concrete material removal depths after hydrodemolition, and areas where the GPR interpretations indicated no evidence of deterioration generally corresponded to areas with minimal concrete removal. Findings suggest that the correlation between the GPR interpretations and concrete removal depths can be improved quantitatively by adjusting the GPR threshold values used in the interpretation, although the major challenge will be to understand how to determine the threshold values without having the benefit of the control data. Finally, recommended parameters are provided for ground-coupled GPR data acquisition, processing, and interpretation.125