An automated signal processing system for the signature analysis of radar waveforms from bridge decks

This paper describes the results of a project which employed impulse radar to detect faults existing beneath the surface of an asphalt-covered bridge deck at Papineau Creek, Ontario. A simple but enlightening mathematical analysis is provided which accurately predicts the waveforms actually observed. The methodology clearly demonstrates the usefulness of impulse radar as a diagnostic tool in remote sensing. Amongst the problems discussed and solved are: the identification of faults due to debonding, scaling, and delamination; the measurement of asphalt thickness at selected locations on the bridge deck and hence the determination of average thickness over the entire bridge deck; and the automated processing of the data using a computer. A comparison of the radar detected faults with those detected using conventional methods is provided. A set of parameters has been developed which permits data to be reduced to a simple set of measurements that can be plotted for visual inspection.