Hope College Department of Physics and Engineering Research Experiences for Undergraduates Summer 2006 Project Summary

Externally bonded fiber-reinforced polymer (FRP) composites are currently used to strengthen existing reinforced concrete structures. Infrared thermography (IRT) is a nondestructive evaluation tool that can be used to determine how well a composite is bonded to the concrete substrate. Before IRT can be applied effectively, the thickness of the composite should be known. This research provides preliminary experimental data for glass/epoxy composites bonded to concrete with laminate thicknesses ranging from 1 mm to 4 mm. Two 500 W halogen lamps were used to heat the surface and a thermal imaging system was used to measure the temperature response over time. The resulting series of thermal images were normalized to remove the effects of non-uniform heating and the variation in the normalized temperature response was compared for the different FRP composite thicknesses. Results indicate that that normalized temperature response is an excellent indicator of relative thickness.

*This material is based upon work supported by the National Science Foundation under NSF-REU Grant No. 0452206.

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Presentations:

Brown, J., Baker, R and Kallemeyn, L. (2007). "Heat Transfer Mechanisms in Fiber-Reinforced Polymer Composites Bonded to Concrete". SPIE Defense and Security Symposium: Thermosense XXIX, Orlando, Florida, April 9-13, 2007 Vol 6541

Brown, J., Baker, R and Kallemeyn, L. (2008). "Crack detection and fatigue related delamination in FRP composites applies to concrete". SPIE Defense and Security Symposium: Thermosense XXX, Orlando, Florida, March 16-20, 2007

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