GRADATION MODIFICATION TO IMPROVE BITUMINOUS MIX PROPERTIES

The primary objective of this study was to determine the effects on asphalt mix properties and performance of proposed specification revisions for gradation, penetration, ductility, and Marshall stability. A factorial laboratory experiment was devised using gradation, asphalt source, aggregate source, and asphalt grade as primary study parameters. Three evaluation techniques were utilized. First, complete Marshall design procedures were followed for all cells and data analyzed. Second, a panel of experts was formed and using modified Delphi analysis techniques basis recommendations were formulated. Finally, specimens from selected cells were tested to determine Creep compliance, permanent deformation and fatigue characteristics. Distress and performance predictions using the VESYS IIM computer program were then generated for average conditions in Utah. A more coarse gradation was adopted for bituminous surface coarses, and the range of air voids was altered to 3-5%. Retained strength was recommended for use in the immersion-compression procedure, and AASHTO Table 2 with ductility modifications was adopted. /FHWA/

  • Availability:
  • Supplemental Notes:
    • Conducted in cooperation with DOT, Federal Highway Administration.
  • Corporate Authors:

    Utah Department of Transportation

    Materials and Research Section, 757 West Second South
    Salt Lake City, UT  United States  84114
  • Authors:
    • Anderson, D I
    • Betenson, W B
    • Shepherd, L W
  • Publication Date: 1977-9

Media Info

  • Pagination: 81 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00183997
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • ISBN: 500-931
  • Report/Paper Numbers: FHWA-UT-78-77-7 Final Rpt.
  • Contract Numbers: PL-PR-1(15-16)
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Dec 12 1978 12:00AM