EVALUATION OF DIELECTRIC MEASUREMENT APPARATUS FOR DETERMINING PAVEMENT DENSITY, FINAL REPORT

AN ELECTRONIC DEVICE WHICH WAS SENSITIVE TO THE DIELECTRIC VALUE OF DIFFERENT MATERIALS WAS DESIGNED AND CONSTRUCTED IN AN ATTEMPT TO MEASURE ASPHALT CONTENT OF ASPHALT MIXES. SUBSEQUENT TESTS WITH THE INSTRUMENT SHOWED THAT IT WAS MORE SENSITIVE TO ASPHALT MIX DENSITY THAN TO ASPHALT CONTENT, AND SO IN 1968, IT WAS MODIFIED FOR USE AS A DENSITY METER. DURING THIS EVALUATION OF THE DIELECTRIC DEVICE, SEVERAL CHANGES WERE MADE WHICH RESULTED IN AN UNEXPECTED IMPROVEMENT AND PERFORMANCE OF THE DEVICE. IT APPEARS THAT THE INSTRUMENT IS FULLY CAPABLE OF MEASURING DENSITY OF ASPHALT MIXES. THERE ARE ALSO VERY GOOD INDICATIONS THAT IT COULD BE EQUALLY VALUABLE AS A SENSOR FOR CONTINUOUS MEASUREMENTS OF DENSITY OVER A FRESHLY PLACED ASPHALT MIX PAVEMENT. THE DEVICE STILL APPEARS TO BE SENSITIVE TO THE CONTACT PRESSURE BETWEEN THE CAPACITOR PLATES AND THE ASPHALT MAT. ANOTHER LIMITATION IS THAT WITH MIXES OF ASPHALT CONTENT LOWER THAN 4%, SOME CORRECTION OF RELATIVE DENSITY READING MUST BE APPLIED TO OBTAIN CORRECT ABSOLUTE DENSITY VALUES. HOWEVER, THE LOW COST AND IMMEDIATE READOUT CAPABILITY OF THIS DEVICE MAKES IT A VERY ATTRACTIVE INSTRUMENT FOR CONTROLLING THE LAYDOWN OF ASPHALT MIXES. /CDH/

  • Supplemental Notes:
    • 20 Pp, 13 FIG
  • Corporate Authors:

    Colorado Department of Highways

    Planning and Research Division, 4201 East Arkansas Avenue
    Denver, CO  USA  80222
  • Publication Date: 1969-7

Subject/Index Terms

Filing Info

  • Accession Number: 00211695
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Nov 8 1971 12:00AM