Passive infrared thermography as a diagnostic tool in civil engineering structural material health monitoring

Author(s): M. Scott, H. Luttig, M. Strydom, M. Gonelli, D. Kruger, R.G.D. Rankine, T. Broodryk
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 274- 275
Total Pages: 2
Language: English

Abstract: 
Infrared thermography is now a highly evolved non-destructive testing technology with a myriad of proven applications in aeronautical, electrical and mechanical engineering applications. Although it has been successfully used in diagnosing distress in civil structures for two or three decades, civil applications have been limited mainly to qualitative use of this technology due to difficulties in scanning such large objects in a transient state (which can only be passively warmed using unpredictable sunshine) and a lack of appropriate data/experience. The cost of infrared cameras has reduced considerably in recent years but, at the same time, these instruments have become increasingly sophisticated and far better suited to the civil practitioner’s needs. Most of South Africa has an ideal climate for passive thermography since we have been blessed with abundant sunshine and large diurnal temperature swings. Recent collaborative research at the University of Johannesburg has explored the ability of a range of thermal cameras to observe delamination-type defects of different sizes embedded in concrete at different depths from various viewing distances and angles under differing weather conditions and seasons. The fruits of this work will culminate in a guideline document for South African practitioners. A parallel study has developed an emissivity cabinet to accurately measure the range of emissivities of common building materials with different surface finishes and degrees of weathering to provide data necessary for more accurate quantitative estimation of surface temperatures of structural elements. This research has shown that common materials such as concrete and steel may exhibit a wide range of emissivities depending on the method of manufacture and weathering encountered.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00