Relationships between creep slope, wheel tracking rate and ALF deformation at two temperatures

A laboratory study was undertaken to investigate the change in the permanent deformation properties of asphalt with temperature, with a view to throwing light on the different rankings, found for some mixes, by the Accelerated Loading Facility (ALF) and the laboratory creep test. Samples removed from the ALF pavement trial sections were tested in the laboratory at two temperatures using the dynamic creep test and the wheel tracking test. The laboratory data were compared with deformation rates in the initial, ALF "Core Trial", conducted at ambient temperature (maximum pavement temperature approximately 35 degrees Celsius), and the subsequent ALF "Follow Up" trial where the pavement temperature was controlled at 50 degrees celsius. It was found that, while the creep test and ALF deformation rate rankings agreed for mixes with different binders but the same aggregate grading, the creep test did not correctly predict the field deformation resistance of mixes with different aggregate gradings. This is considered to be a serious impediment to employment of the test in a mix design procedure. The wheel tracking test results at 60 degrees Celsius correlated well with ALF deformation rates at 50 degrees Celsius, suggesting that this test may be a useful tool for mix design purposes. The 35 degrees Celsius wheel tracking and ALF deformation data were not well correlated and this may be due to imprecision in the wheel tracking test at this temperature. Mixes manufactured with SBS and multigrade binders had a smaller dependence of deformation rate on temperature than the other ALF mixes. These two binders had a lower temperature susceptibility, using the CarriMed dynamic shear rheometer, than the other mixes. The correlation between binder and mix properties suggests that specification of binder properties, using suitable laboratory tests, may assist in controlling asphalt rutting in the field.

Language

  • English

Media Info

  • Pagination: 3.1-13
  • Serial:
    • Issue Number: 12

Subject/Index Terms

Filing Info

  • Accession Number: 01435607
  • Record Type: Publication
  • Source Agency: ARRB
  • ISBN: 086910683X
  • Files: ATRI
  • Created Date: Aug 24 2012 7:07PM