Stability of conventional bituminous pavements is compromised and rutting rates are accelerated by continually increasing traffic volumes and heavy truck traffic. Stone Matrix Asphalt (SMA) was identified during the 1990 European Asphalt Study Tour (EAST) as a possible replacement mix for heavily trafficked pavements. This report documents Illinois' experience with seven SMA projects. To determine what would best suit Illinois, the Illinois Department of Transportation (IDOT) investigated two different types of mixture gradations, three types of aggregates, and three types of modifiers. Findings to date indicate the three types of aggregates and modifiers performed adequately when designed to the coarser mixture gradation. The smaller SMA gradation type was not as successful. These mixtures generally were tender and flushed. SMAs were very sticky, especially the polymer-modified, and were difficult to remove from trucks and to work by hand. Mixing and laydown temperatures were found to be more critical than for dense-graded mixtures. Plant type (batch or drier-drum) did not affect mixture production. Costs were approximately 40% higher than for dense-graded mixtures. This cost is expected to decrease with experience. The overall successes of the seven projects were variable. These projects will be monitored for performance. IDOT will consider SMA as an alternative to conventional dense-graded mixtures in areas of heavy and congested traffic, areas of heavy truck traffic, and areas where rutting has been a continual problem.

  • Corporate Authors:

    Illinois Department of Transportation

    Bureau of Materials and Physical Research
    126 East Ash Street
    Springfield, IL  United States  62704-4766

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Rademaker, M
  • Publication Date: 1996-1


  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 110 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00720188
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/IL/PR-121, Project IHR-538
  • Created Date: Apr 16 1996 12:00AM