Polk County, Florida
A ground penetrating radar study was performed by GeoView to provide information on pavement thickness of a county road in central Florida. The study area was approximately 5 miles in length and was conducted in both lanes of traffic.
The GPR data was collected using a proprietary road cart with a Mala Pro-Ex dual channel GPR system. Data was acquired simultaneously using both 800 MHz and 2.3 GHz antennas. Penetration depth of the GPR signal ranged from 0.5 to 3 ft below land surface. Data acquisition speed was near to the posted speed limit and ranged from 20 to 30 miles per hour.
A safety vehicle followed behind the data collection vehicle to allow the roadway to remain open during and traffic to flow at normal speeds during the time of survey. Position control for the GPR data was obtained using an integrated differentially corrected GPS system. By using this approach the need to set up a survey benchmarks across the site was avoided, greatly enhancing project efficiency and cost effectiveness. The GPR data was able to successfully image the bottom of the asphalt. Coring data was used to ground truth the GPR data and help determine precise depth calculations. The data also showed several suspected asphalt patches and abrupt changes in roadway construction.