Nondestructive evaluation of civil infrastructure is increasingly important in the modern world to assess structures, predict longevity, and prescribe rehabilitation or replacement. For concrete bridge decks, one emerging diagnostic technique is vertical electrical impedance (VEI) testing, which is a nondestructive evaluation technology that quantitatively assesses the cover protection offered to steel reinforcement. Because VEI testing is still a relatively new approach to bridge deck inspection, additional studies are needed to increase the interpretability of VEI data. This thesis increases VEI interpretability with two advances. The first advance, presented in Chapter 2, offers an analytical model for interpreting VEI measurements of cracked bridge decks. The analytical model allows crack depth to be predicted from VEI measurements. The second advance, presented in Chapter 3, offers an interpretation of VEI measurements within the context of other, more typical, nondestructive bridge deck measurements. Surface cracks cause a significant acceleration of chloride ingress towards the steel reinforcement because they provide a direct path for chlorides to penetrate the concrete cover and corrode the steel. Estimating the depth of these cracks enables better prediction of chloride loading and influences predictions of service life. An invertible analytical model for VEI measurements of cracks based on a cylindrical dipole approximation is presented. This model is validated with numerical simulations, laboratory experiments, and destructive field tests performed on concrete parking garage decks. Inversion of the model permits depth estimation of cracks and a quantitative interpretation of VEI measurements for this specific concrete defect. An additional study was performed on a newly constructed bridge deck in Midvale, Utah, that was subject to an unexpected rainstorm during construction. Several forms of nondestructive testing, including VEI testing, were performed on the deck. Statistical analysis of the tests permitted assessment of the bridge deck. Comparing VEI testing with these other NDT methods has not been done before, and the results of this work will assist those who are unfamiliar with VEI with interpretation of VEI data in the context of other, more typical NDT techniques.



College and Department

Ira A. Fulton College of Engineering and Technology; Electrical and Computer Engineering



Date Submitted


Document Type





Bridge deck, concrete, nondestructive evaluation, vertical electrical impedance



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Engineering Commons