Application of Thermal IR Imagery for Concrete Bridge Inspection

October 20, 2011 Dow 642, Thursday, 4-5 pm


Khatereh Vaghefi, Graduate Student of CEE

The authors of this presented paper include: Khatereh Vaghefi, H.A de
Melo e Silva, D.K. Harris, T.M. Ahlborn.

Public welcome.


Detecting subsurface cracks and delaminations within concrete bridges
has been always a challenge for bridge inspectors and transportation
authorities. This type of subsurface deterioration can appear either on
the bridge deck or girder; however, delaminated areas underneath the
bridge can be more critical as it raises safety issues for passing by
traffic. Visual inspection, which is a common practice technique for
bridge condition evaluation, is not able to provide enough information
of internal defects and deteriorations. Although, recent developments in
non-destructive techniques provide bridge inspectors with advanced tools
and methods for bridge inspection, most of these methods are either
expensive or difficult to apply.

Thermal Infrared imagery is a technology based on measuring the radiant
temperature of an element, such as a bridge deck. Subsurface
delaminations and anomalies appear as hot spots on the thermal IR image
during the day as they interrupt the heat transfer through the concrete.
In this way, delaminations can be detected before turning to spalls on
the bridge. Applying this technology can enhance the current bridge
inspection practice as well as providing useful information for
maintenance and repair decision making. The purpose of this paper is to
review the recent developments in this field and to investigate the
feasibility of thermal IR application for regular bridge inspections.