The need to incorporate elastic and viscoelastic models into a practical flexible pavement design procedure is well founded. A limited verification of the VESYS IIM design procedure, and an investigation of the possiblities of implementing the system in Utah were carried out. The program is based on a 3-layer model corresponding to the bituminous, base gravel and soil materials. The test samples were formed using the identical asphalts and gravel materials place in the selected pavements. Air-tight containers were used to store the asphalts from the time of construction, and were found to be relatively unaged. The indirect tensile test was employed to obtain the creep compliance, permanent deformation, and fatigue data needed to generate the projected performance data. The base gravel and soil materials were tested using a cylindrical test specimen under confining pressure to obtain the creep compliance and permanent deformation data for the second and third layers. Actual traffic data measured over the pavement life was used as input. Estimates of the performance of some pavements were produced, and compared with the measured performance data. These predictions were found to be adequate for the magnitudes and times measured. Future work in the study will evaluate the procedure in a wider range of performance data, pavement materials, traffic loadings, and environmental conditions. Implementation of the procedure in its present form would require significant changes in the structure of Utah's present overall design scheme. The obligations of various state organizations would require alteration. Also, some form of prediction of transverse, temperature-associated cracking would be necessary in many states to obtain an optimum design based on performance. Preliminary results show that the VESYS II M program has great potential, and every effort should be made to fine tune the models and incorporate the procedure into practical application /Author/

Media Info

  • Features: Figures; References;
  • Pagination: p. 148-157

Subject/Index Terms

Filing Info

  • Accession Number: 00170212
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Mar 14 1978 12:00AM