Nondestructive Bridge Deck Testing with Air-Coupled Impact-Echo and Infrared Thermography

TLDR

The advantages and limitations of air‑coupled impact‑echo and infrared thermography for defect characterization are discussed. The study proposes a simple data fusion technique to enhance the effectiveness of individual test data. The authors evaluated air‑coupled impact‑echo and infrared thermography on a full‑scale simulated reinforced concrete bridge deck with delamination and cracking defects, assessing each method’s consistency and sensitivity. The study found that combining air‑coupled impact‑echo and infrared thermography provides a practical, consistent, and rapid in‑situ evaluation of reinforced concrete bridge decks, with each method individually showing good agreement with actual defects.

Abstract

Two different nondestructive test (NDT) methods, air-coupled impact-echo (IE) and infrared (IR) thermography are evaluated on a full-scale simulated reinforced concrete bridge deck containing simulated delamination and cracking defects. The IE data are presented as two-dimensional frequency maps and spectral B-scan lines. The IR data are presented as temperature maps on the concrete surface. The lateral boundaries of the detected delaminations are also indicated in the images. The results obtained from each of the individual NDT methods show reasonably good agreement with most of the actual defects. The advantages and limitations of each method to characterize defects are discussed. The consistency and sensitivity of each method are also investigated. Finally, a simple data fusion technique is proposed to improve effectiveness of the individual test data. The findings from this study demonstrate that the combination of air-coupled IE and IR thermography tests is a practical option for consistent and rapid in situ evaluation of reinforced concrete bridge decks.