Pavement layer thickness data are required for network- and project-level pavement management. Until now, adequate amounts of these data were difficult to obtain because of the cost, time, and interference involved in taking cores. A new nondestructive, noncontact method for thickness measurement is available and can be implemented from a survey vehicle moving at highway speed. The technology incorporates horn antenna radar equipment coupled with customized processing software called PAVLAYER. This report describes an accuracy evaluation of this technology in which results from 10 SHRP Long Term Pavement Performance (LTPP) asphalt pavement sections in 10 states were compared to core data. The results were evaluated in two steps: (1) "blind", without benefit of prior information from any core data; and (2) calibrate, using core data at one location per site. The evaluation showed deviations from cores of ± 8% for blind evaluations and ± 5% when calibration cores were used. (Author/publisher)
Abstract