The final report of the first Phase of this project recommended the fabrication and development of two items of pavement test equipment, the duomorph and the mobile acoustic crack detector. A working model of the duomorph, satisfactory for the evaluation of the dynamic moduli of most asphalt pavements, was fabricated and delivered along with the necessary power supply and signal conditioning circuitry necessary to make it operate. The process for reducing the data obtained from the sensor is described. The necessary charts and graphs are included as is an expanded checklist for duomorph operation. Stiffnesses obtained using the duomorph are compared with resilient moduli measured in the laboratory. These comparisons are encouraging. The development of a mobile crack detector progressed well except for difficulty with the rolling acoustic transmitter. The mobile transmitter consistently sent more energy to the receivers through the air than through the pavement. This served to mask the effects of intervening pavement cracks on the signal to the extent that the detector is ineffectual. Further development will require better acoustic isolation of the transmitting device. Finally, under the auspices of the program, the dynamic deflection test van fabricated for the FHWA by James Cox and Son was evalauted. The characteristics of the van are detailed and methods of correcting errors inherent in the system are suggested. (FHWA)

  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  United States  76011
  • Authors:
    • Noel, J
    • Boggess, R
    • Swift, G
  • Publication Date: 1978-6

Media Info

  • Pagination: n.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00315049
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-RD-80-099 Final Rpt., FCP 35D1-022
  • Contract Numbers: DOT-FH-11-8264
  • Files: TRIS
  • Created Date: Aug 5 1980 12:00AM