摘要: |
Pavement engineers routinely utilize mechanistic-based models for pavement rehabilitation design and for assessing the remaining service life of existing pavement structures. Dynamic and rolling load equipment is used to measure pavement response to those applied loads. The analytical models that utilize such data are dependent on the availability of accurate pavement layer thickness values at the load application points. Ground-penetrating radar (GPR) technology has been used to quantify pavement structures, but the technique has not provided sufficient accuracy or reliability to gain general acceptance. GPR accuracies have generally improved when core data are made available for system calibration; however, the number of cores required to maintain acceptable accuracies effectively defeats the purpose of nondestructive measurements. A new GPR technology, known as Road Radar, takes a different approach to the thickness measurements of multiple pavement layers in pavement structures. This technology uses multiple antennas that provide accurate non-intrusive thickness measurements of multiple layers from 50 mm to greater than 2,000 mm without benefit of any destructive calibration procedure, such as drilled cores. The Road Radar technology, designed into the Road Radar System and proven through extensive field trials and data-acquisition programs, is described in this report. Comparative analysis is presented of pavement structure thickness measurements, using both Road Radar measurements without core calibrations and drilled core measurements. The results of these comparisons are reported for a number of individual projects, as well as statistical analysis performed on approximately 150 pieces of paired data "pooled" from a number of field test sites. |