THE FATIGUE OF FLEXIBLE PAVEMENTS

Five asphaltic concrete pavements, each of which measured 20x30 ft. and contained two test areas, were constructred on a 48" compacted clay subgrade. Certain of these pavement areas were fatigue loaded through concentric rings composed of truck tire rubber by superimposing one dynamic 10 Hz haversine pulse on a small static load every second to simulate a continuous line of wheel loads traveling in identical wheel paths 50' apart 15 40 MPH. Surface tangential strain, surface deflection and temperature sensors were palced at a number of radii from the load plate centerline and recorded periodically throughout each test. The fatigue of four test areas, as evidenced by visible cracking, was observed closely and noted in a log book. Asphalt and compacted subgrade samples were returned to the laboratory for the determination of structural strength and physical properties. The results of these tests were entered into the Chevron n-layer program along with a number of hypothetical moduli for the natural subgrade underlaying these layers. Theoretical strain and deflection profiles obtained from these calculations were compared to measured profiles to determine the best average apparent modulus for this semi-infinite layer. Trapezoidal specimens were sawed from asphalt pavement blocks and fatigue loaded with one 10 Hz haversine pulse per second over a wide range of temperatures and strain levels. An equation relating these quantities to fatigue life was developed and coupled with a theoretical pavement fatigue model to predict the time of initial surface cracking on the four test areas where visible cracks were observed. /AUTHOR/

  • Supplemental Notes:
    • Presented at the Third International Conference on the Structural Design of Asphalt Pavements, Grosvenor House, Park Lane, London, England, Sept. 11-15, 1972.
  • Corporate Authors:

    International Conf Struct Design Asph Pvmts (3rd)

    University of Michigan, Department of Civil Engineering
    Ann Arbor, MI  United States  48104

    International Conf Struct Design Asph Pvmts (3rd)

    University of Michigan, Department of Divil Engineering
    Ann Arbor, MI  United States  48104

    Interrational Conf Struct Design Asph Pvmts (3rd)

    University of Michigan, Department of Civil Engineering
    Ann Arbor, MI  United States  48104
  • Authors:
    • Coffman, B S
    • Ilves, G J
    • Edward, W F
  • Conference:
  • Publication Date: 1972-9

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 590-607
  • Serial:
    • Volume: 1

Subject/Index Terms

Filing Info

  • Accession Number: 00261934
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Oct 22 1974 12:00AM