Field Testing of Hand-Held Infrared Thermography, Phase II Final Report Volume II: New Technologies.

摘要

This report is the second of two volumes that document results from the pooled fund study TPF-5 (247), Development of Handheld Infrared Thermography, Phase II. The interim report (volume I) studied the implementation of handheld thermography by participating state Departments of Transportation (DOTs). This final report (volume II) provides a summary of field testing conducted to evaluate the capabilities of two different IR imaging technologies for detecting subsurface damage in concrete. The IR-UTD technology collects thermal images over a period of time; these data are processed to measure thermal inertia of a material. The IR-UTD technology is an entirely new approach for imaging damage in concrete structures. The IR-DSS technology automatically captures thermal images while the system is moved from one position to another. The IR-DSS technology produces images based on the radiant thermal energy from a material in the same manner as other typical thermal imaging systems. However, the IR-DSS has a unique design that allows the system to be implemented from different mobile platforms and uses a precision encoder to trigger data collection. In general, it was found that the IR-UTD technologies had capabilities that exceeded the capabilities of conventional IR imaging. The technology provided highly accurate data that documented the size and shape of delaminations in bridge decks and other structures. The IR-UTD technology also provided data on the depth of damage and could image the structural features of a bridge. Traffic control was not required to implement the IR-UTD technology. The IR-DSS capability was demonstrated to include the ability to produce spatially-referenced images that provided accurate depictions of subsurface damage, and these data were presented to-scale in a plan-view image of an entire deck. Traffic control was required to implement this technology, because the travel speed of the system is limited to < 10 mph.