Stiffness, as a material characteristic of asphalt cements, is attracting more attention in asphalt technology. This paper shows the quantitative relations between viscosity and stiffness and explains how the shear modulus and viscosity found by a constant stress rheometer can be used to evaluate stiffness. Experimental data from creep curve studies are given for a number of asphalt cements. The shear modulus is shown as the limiting asymptote that intersects the viscosity term asymptote at a stiffness limit time. These two asymptotes delineate the complete stiffness curve. Characteristic stiffness is shown to be a material property, but knowledge of the system is prerequisite to its use in design, if the absolute deformation is to be considered. Variations in stiffness with shear rate (stress), temperature, and time are illustrated by data on absolute measurments for eight different types of asphalts at temperatures from 25 down to -5 deg C (77 to 23 deg F). The addition of vicosity and stiffness data at 5 deg C (41 deg F) to the usual viscosity data at 25 and 60 deg C (77 and 140 deg F) provides a better rheological profile for asphalt cements at low ambient temperatures than has previously been reported. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 1-11
  • Monograph Title: Bituminous concrete materials, mixtures, and additives
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00185289
  • Record Type: Publication
  • ISBN: 0309026881
  • Files: TRIS, TRB
  • Created Date: Jan 13 1979 12:00AM