Three gradations (coarse, medium fine) of natural pit-run aggregate with low asphalt content were tested by conventional methods and in a more sophisticated triaxial testing system. Material properties such as stress non-linearity, stiffness and Poisson's ratio are discussed and statistically correlated in terms of asphalt content, temperature and air voids. A preliminary formula correlating the material resilient modulus and Hveem stability is also presented. The asphalt cement used was 85-100 pen. A total of 27 specimens representing 9 different mixtures were tested (3 asphalt contents and 3 gradations). Conventional tests included the standard density, air voids and the Hveem stability and cohesion (performed at temperatures under which the triaxial tests were performed). The tests carried out in the triaxial test system were: the repeated load (axial and radial), creep (constant axial compressive stress) and dynamic (sinusoidal axial). The literature on the subject of non-linearity of pavement materials is briefly reviewed. The resilient modulus studies led to two sets of parameters based on the resilient strains and the total strains. Studying these parameters led to the following observations: mixtures with lower air voids were closer to agreement with the condition of cross-isotropy; the value of the resilient modulus decreased sharply with temperature and stress durations; the average value of Poissons ratio increased with temperature; and at low temperatures, no appreciable difference was noticed between the values of the parameters based on the resilient strains and those based on total strains. Comments and observations are made on the modulus of total deformations. The studies lead to the conclusion that stress non-linearity for ATB is insignificant within the practical range of temperature and stresses. This study was concerned with establishing the stress-strain relationship for ATB. This relationship is used in predicting stresses and deformations under some loading at some environmental conditions. If this type of characterization is obtained for different pavement materials, and if the failure criteria for such materials are well established, the rational design method, becomes a reality.

  • Supplemental Notes:
    • Proceedings of the meeting held in Houston, Texas, February 1973.
  • Corporate Authors:

    University of Minnesota, Minneapolis

    155 Experimental Engineering Building
    Minneapolis, MN  USA  55455
  • Authors:
    • Awad, I S
    • Rutz, R
    • Terrel, R L
  • Conference:
  • Publication Date: 1973

Media Info

  • Features: Figures; References;
  • Pagination: p. 230-251
  • Serial:
    • Volume: 42

Subject/Index Terms

Filing Info

  • Accession Number: 00127330
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 16 1975 12:00AM