Applicability analysis of IR thermography and discrete wavelet transform for technical conditions assessment of bridge elements

ABSTRACT

Standard procedures for carrying out the inspection of the bridge or the assessment of its technical condition and suitability for use, rely on visual assessment made by the inspector and are in a certain part subjective. The main objective of the article is to analyze the applicability of IR as a tool to support the inspections of the structure and equipment elements of bridges. We are looking for the relationship between temperature distribution on an element surface (registered by an infrared camera) and hidden defects, which may be associated with, among others, moisture, discontinuity or delaminations in concrete structures. The study was divided into three parts: numerically simulated experiments of transient heat transfer, laboratory tests of reinforced concrete (RC) slab and some in-situ tests of a real bridge. To improve the effectiveness of damage detection, discrete two-dimensional wavelet transformation was applied.

KEYWORDS:

• Active and passive IR thermography
• bridge inspection
• damage detection
• reinforced concrete
• two-dimensional discrete wavelet transformation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Politechnika Poznańska [01/12/DS-PB/0482];Politechnika Poznańska [02/22/DS-PB/1318].

Notes on contributors

Leszek Różański

Leszek Różański Post doc in Division of Metrology and Measurement Systems in the Institute of Mechanical Technology, Poznan University of Technology. Head of IR thermography lab. He graduated in Automation Control Engineering and Electrical Metrology from the Faculty of Electrical Engineering at Poznan University of Technology, and in Physics from the Faculty of Mathematics, Physics and Chemistry at Adam Mickiewicz University. He deals with theory and design of thermal imaging systems, thermal diagnosis and applications of vision systems in metrology of geometrical dimensions.

Krzysztof Ziopaja

Krzysztof Ziopaja received M.Sc. and Ph.D. degree in Civil Engineering at Poznan University of Technology (PUT). Since 2009, he has been employed as Assistant Professor at the Department of Bridges and Railway Roads in the Institute of Civil Engineering at PUT. His area of scientific activity is primarily associated with non-destructive methods serving to locate defects in material and engineering structures, numerical modeling and simulating the actions of static and dynamic loads, including the flow of heat in solids. He specializes in one- and two-dimensional discrete wavelet transformation.