EVALUATION OF DIELECTRIC MEASUREMENT APPARATUS FOR DETERMING DETERMING PAVEMENT DENSITY

SINCE 1966 AN EVALUATION PROJECT HAS BEEN UNDERWAY TO STUDY ASPHALT PAVEMENTS BY MEASURING ITS DIELECTRIC PROPERTIES. ORIGINALLY, THIS PROJECT WAS DIRECTED TOWARD ASPHALT CONTENT, HOWEVER, IT WAS DETERMINED THAT ASPHALT DENSITY HAD A RELATIONSHIP TO DIELECTRIC PROPERTIES. AFTER A SERIES OF DEVELOPMENTS AND MODIFICATIONS A DIELECTRIC DEVICE WAS DEVELOPED THAT IS RELATIVELY EASY TO OPERATE AND GIVES QUICK AND RELIABLE RESULTS. THE ELECTRONIC COMPONENTS INCLUDE TWO 6 VOLT BATTERIES, AND OSCILLATOR TO CONVERT DC CURRENT TO AC FOR THE SENSING FIELD, AND TWO SETS OF SENSING ELECTRODES (CAPACITOR PLATES). A MILLIAMMETER AND AMPLIFIER ARE USED TO INDICATE THE VOLTAGE DEVELOPED ACROSS THE INDUCTANCE CAPACITANCE RESONANCE CIRCUIT. OUTPUT ON THE MILLIAMMETER INDICATE CHANGES IN DENSITY OF ASPHALT AS THE CAPACITOR PLATES SLIDE ACROSS THE PAVEMENT. UNTIL RECENTLY, LARGE TEMPERATURES HAVE INFLUENCED THE PERFORMANCE OF THE ELECTRONIC COMPONENTS CAUSING SPORADIC READINGS. RECENT MODIFICATIONS HAVE BEEN MADE IN THE DEVICE REDUCING THIS PROBLEM TO A MINIMUM. THE EXISTING DEVICE, WITH PROPER USE, CAN BE VERY USEFUL IN MEASURING THE DENSITY OF ASPHALT PAVEMENTS.

  • Supplemental Notes:
    • Contract 1479
  • Corporate Authors:

    Colorado Department of Highways

    Planning and Research Division, 4201 East Arkansas Avenue
    Denver, CO  United States  80222
  • Authors:
    • Donnelly, D E
    • Swanson, H N
  • Publication Date: 1972-2

Media Info

  • Pagination: 37 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00206532
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: Finial
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: May 15 1974 12:00AM