IMPROVED FRAMEWORK FOR PREDICTING PERMANENT DEFORMATION IN ASPHALT LAYERS

When permanent deformation in asphalt pavements is predicted by elastic analysis and repeated-load triaxial testing, problems arise in the tension zone because of tensile stress in both horizontal directions. This stress situation cannot be directly reproduced in the triaxial test. An approach is suggested to deal with this problem in particular and with pavement materials characterization in general. It recognizes that strains developing in any particulate material depend on the combination of mean normal stress and octahedral shear stress. These stress invariants are functions of the principal stresses but are independent of their directions. Triaxial tests can be more flexibly used by reproducing the appropriate values of these stress invariants rather than the in situ principal stresses. Measurement of vertical and lateral strains during the test permits the evaluation of corresponding strain invariants that can be used to calculate the in situ vertical strain, which is of interest in rut depth prediction. Elastic analysis indicates that the suggested approach should lead to better predictions of permanent deformation in high temperatures and thick layers. The very high tensile stresses associated with lower temperatures and thinner layers still, however, present a problem because only one tensile stress can be applied in the triaxial test.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 18-30
  • Monograph Title: Pavement and soil characteristics
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00126816
  • Record Type: Publication
  • ISBN: 0309023882
  • Files: TRIS, TRB
  • Created Date: Dec 16 1975 12:00AM