In 2012, Infrasense, Inc. completed a subsurface pavement thickness survey of 290 lane miles of the Parks Highway between Anchorage and Fairbanks, Alaska using ground penetrating radar (GPR). The thickness investigation employed the use of two different frequency antennas, designed to achieve the optimum tradeoff between resolution and depth of penetration. The objective of the work was to accurately characterize the pavement structure while reducing the number of cores that the state typically uses. By reducing the need for cores, the entire 290 mile project section was able to be tested within the limited thaw season, allowing for more immediate planning decisions to be made.
Typical pavement structure thickness data was collected with the higher resolution air-coupled radar antenna. The deeper penetrating lower frequency antenna was able to capture areas where the pavement structure was unusually deep (greater than 3 feet). All data was synchronized with a Global Positioning System (GPS) to provide coordinate locations for the detected pavement thicknesses. Data collection was performed in a single day at normal highway speeds, allowing traffic to flow without any disruption.