Evaluation of the Rolling Density Meter for Rapid Continuous Measurement of Asphalt Mixture Density

The rolling-density meter (RDM) is a ground-penetrating radar (GPR)-based system tailored for rapidly and continuously measuring asphalt mixture density. This research analyzed the readiness level of the RDM and provided recommendations for how this technology could be used in quality control/quality assurance (QC/QA). To evaluate the RDM precision, four antennas were used in a laboratory environment to test six different materials. Increasing the number of scans averaged did improve the precision. For materials similar to those tested, the dielectric measurement was repeatable within 0.15 and reproducible within 0.22 or better. The RDM was deployed on six field projects for multiple paving days. Researchers evaluated the reproducibility of calibration curves, precision and bias of the system and of a nuclear density gage, and distribution of predicted air voids. Overall air void calibrations were good with an average R² value of 0.76. The calibration curves were unique for different paving projects, and in some cases unique for different days of paving. Using different antennas for calibration did not influence the resulting calibration curves. The RDM was more precise than the nuclear density gauge and unbiased. The field data were used to perform a producer and consumer risk analysis. Different pay factors and percent within limit characterizations were calculated. The single-core acceptance method exposes producers and consumers to significant risk while density profiling with the RDM effectively eliminates risk. An alternative 3D radar system was deployed on three test sections. The system produced high resolution scans of the asphalt surface and subsurface. Further work is needed to tailor data processing for density testing. Researchers recommend adopting the draft test method and equipment specifications for rapid full-coverage measurements of asphalt mixture density using GPR.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Technical Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 96p

Subject/Index Terms

Filing Info

  • Accession Number: 01692006
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-17/0-6889-R1, 0-6889-R1
  • Contract Numbers: 0-6889
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jan 28 2019 8:08AM