CREEP TEST: A KEY TOOL IN ASPHALT MIX DESIGN AND IN THE PREDICTION OF PAVEMENT RUTTING

The paper reviews the rut depth estimation procedure based on static creep testing and incorporated in the overall Shell pavement design procedure. It shows that for practical purposes the pavement asphalt can be subdivided into three sub-layers, based on consideration of temperature gradients and effective viscosity values in relation to the accuracy with which viscosity values can be determined. Backgrounds and accuracy are discussed for the construction of a chart showing the relation between mean monthly air temperatures and montly effective pavement temperatures for various sub-layers and sub-layer thicknesses. In relation to the mix characteristics to be used as input data in the procedure, it is emphasized that creep curves must be used which are representative of practice. The system of converting axle load data into an equivalent number of standard single design wheels is discussed in detail, especially the influence of mix type. The average stresses in the asphalt layers are of utmost importance. Detailed attention is given to the procedure for determining average stress values over time intervals with varying temperatures and temperature gradients. Finally, some examples are worked out which illustrate the procedure and the interrelationship between mix design and pavement design.

  • Supplemental Notes:
    • From the Technical Session, Lake Buena Vista, Florida, 13-15 February 1978.
  • Corporate Authors:

    University of Minnesota, Minneapolis

    155 Experimental Engineering Building
    Minneapolis, MN  USA  55455
  • Authors:
    • Van de Loo, P J
  • Conference:
  • Publication Date: 1978

Media Info

  • Features: References;
  • Pagination: p. 522-557
  • Serial:
    • Volume: 47

Subject/Index Terms

Filing Info

  • Accession Number: 00197235
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Sep 15 1979 12:00AM