The stiffness of asphalt-aggregate mixes is important in determining how well a pavement performs, and is an essential property for analyzing pavement response to traffic loading. A study for stiffness determination of asphalt-aggregate mixes was conducted as a part of Project A-003A of the Strategic Highway Research Program (SHRP). Its purpose was to evaluate the sensitivity of the axial (compressive) and diametral (indirect tensile) resilient stiffness to mix and test variables and to compare the axial and diametral resilient stiffness of 16 mixes tested under various temperatures, stress levels, and loading frequencies. Results of this study indicate that both axial and diametral resilient stiffnesses are sensitive to mix and test variables, including asphalt type, aggregate type, air-void content, and temperature. However, axial and diametral testing of mixes yield different estimates of their resilient stiffnesses. Diametral resilient stiffness computed using an assumed Poisson's ratio of 0.35 generally exceeds axial resilient stiffness by an average of approximately 35 to 45%. SHRP Project A-003A experience suggests that the indirect tension test is not accurate for relatively weak specimens at temperatures as high as 60 deg C (104 deg F), and tension may not be reliable even at moderately high temperatures [40 deg C (140 deg F)] due to excessive vertical permanent deformation. The influence of mix and testing variables on resilient stiffess may be different depending on whether loading is in axial compression or indirect tension. By inference, differences in mix design and structural pavement design may result depending on the type of testing system used to estimate mix stiffness.


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 135-143
  • Monograph Title: Hot-mix asphalt design, testing, evaluation, and performance
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714841
  • Record Type: Publication
  • ISBN: 309061563
  • Files: TRIS, TRB
  • Created Date: Dec 4 1995 12:00AM