Measuring Asphalt Pavement Density with a GPR-based Sensor: A Case Study

Summary During the construction of asphalt pavements, one of the most important parameters critical to pavement longevity is its density. Pavements need to contain enough air voids to allow some plastic deformation and at the same time, have low enough air voids to prevent water ingress and moisture damage. Being able to map density during emplacement can help control asphalt installation leading to greater pavement life. We have recently presented a new instrument, the Pavement Density Profiler (PDP), which is designed to be a simple, easy-to-use instrument that enables the pavement industry to rapidly assess the compaction of hot mix asphalt (HMA) pavements. In this paper, we present PDP test results performed in cooperation with the Minnesota Department of Transportation on a newly paved section of road. The main conclusions of this testing are that the current PDP is far simpler to use, that instrument factory calibration is reliable, and that the translation to density still needs serious industry assessment.