Non-Destructive Evaluation of Concrete Components Using Infrared (IR) Thermography for Void Detection and Moisture Evaluation (05-0710)
Rudaba Chowdhury, Wayne State University
Upul Bandara Attanayake, Western Michigan University
Haluk M. Aktan, Western Michigan University

For the field evaluation of safety and serviceability of transportation structures robust NDT techniques are needed. The main objective of the field investigation being the identification of distress, types and states on the structural elements, NDT techniques capable of identifying the early signs of distress are most useful. Infrared (IR) thermography is a contact-less NDT technique that uses the surface temperature distribution of an object to assess the surface and subsurface internal variability of the structural components. This paper describes the NDE of void and presence of moisture in concrete using IR thermographic testing techniques by analytical, numerical, experimental, and field investigation. Analytical and numerical modeling is used to predict the experimental results and evaluate the potential testing procedures and aid further development of the testing technique. Studies towards developing an IR thermographic defect (void) detection and moisture assessment procedure for concrete bridge components are described. The need for defect (void) detection is based on comprehensive fieldwork on concrete bridge barriers. The field study showed that voids that form due to lack on consolidation during slip forming of concrete barriers result in rapid deterioration of these concrete structures (1). Void detection by IR thermography can be a quality control and assurance tool (QC/QA) for construction acceptance. The moisture assessment is also based on ongoing field inspection of side-by-side box-beam bridges. Rapid tendon corrosion is detected around the concealed portions of the box beams. Assessment of moisture along the underside of the bridge can predict the location of potential tendon corrosion. Upon the identification of zones of moisture, preventive maintenance actions can be developed to abate moisture ingress.