Correlation of some parameters in GPR measurement data with quality properties of pavements and concrete bridge decks

In order to develop faster and more objective Ground Penetrating Radar data interpretation methods, the University of Qulu and the Finnish National Road Administration have been studying the possibilities of using certain parameters obtained from GPR data to describe the quality of asphalt and concrete structures in roads and bridges. The majority of the test surveys were performed with ground coupled antennae, which involved problems with antenna coupling and ringing. Consequently a special software was developed to reduce antenna ringing and background noise, to trace reflection interfaces and to calculate amplitude ratios. The amplitude ratio R1, R2 theory described by Chung and Carter (1990) for aircoupled antennae was also tested with ground-coupled ones. The software was tested with bridge and road data in which the thicknesses of the structures and their material properties were known.