This research project seeks to explore the use of modified macadam base construction for shoulders. Two macadam base shoulder designs were developed and constructed for this project. A new roadway embankment and P.C.C. pavement were constructed on a section of US 6 east of Adel in Dallas County, Iowa. The macadam base shoulders were constructed adjacent to the pavement as part of the project. The north shoulder was finished with a choke stone course and bituminous surface treatment and the south shoulder was finished with a two inch layer of Type B Class II asphalt concrete. Macadam stone base shoulders can be built with relatively minor construction problems with comparable strength and less cost than asphalt treated base shoulders. The macadam stone base shoulders have performed well with very little maintenance necessary. The improved drainage substantially reduces deterioration of the pavement joints.

  • Record URL:
  • Supplemental Notes:
    • Final Report for Research Project HR-181.
  • Corporate Authors:

    Iowa Department of Transportation

    800 Lincoln Way
    Ames, IA  United States  50010
  • Authors:
    • Ortgies, B H
    • Marks, V J
  • Publication Date: 1981-9


  • English

Media Info

  • Features: Appendices; Figures; Tables;
  • Pagination: 39 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00727050
  • Record Type: Publication
  • Created Date: Oct 8 1996 12:00AM