ESTABLISHING MATERIAL PROPERTIES FOR THIN ASPHALT CONCRETE SURFACES ON GRANULAR BASES. INTERIM REPORT

This report includes the results of an analytical study of thin asphalt pavements over flexible bases to define the engineering properties required for adequate performance. Since truck tire pressures have dramatically increased in recent years, included are the effects of the increased tire pressures on surface tensile strains, base shear stresses, and subgrade compressive strains. A finite element computer program developed for the FHWA was used to calculate vertical and horizontal surface shear pressure distribution for a bias ply truck tire inflated to both 75 and 125 psi. A series of ILLIPAVE runs was made to determine the horizontal tensile strains, lateral shear stresses, and vertical compressive strains for asphalt concrete surfaces 1, 1.5, 2, and 4 inches thick over 8- and 14-inch granular bases having three different moduli and a subgrade soil that is stress-sensitive with an initial modulus of 10 ksi. These results showed that some thin pavement structures cannot provide adequate service, and that design procedures must be upgraded to include materials more resistant to higher strains. To provide adequate service, these surfaces should be either flexible and thin on a stiff, thick base, or be stiff and thick.

• Supplemental Notes:
  • Research performed in cooperation with the Federal Highway Administration. Research Study Title: Performance Considerations and Specifications of Hot-Mix Asphaltic Concrete.
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011

  Texas State Department of Highways & Public Transportation

  Transportation Planning Division, P.O. Box 5051
  Austin, TX  United States  78763

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Roberts, F L
  • Rosson, B T
• Publication Date: 1985-11

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 157 p.

Subject/Index Terms

• TRT Terms: Asphalt concrete; Bias ply tires; Compressive strength; Computer programs; Finite element method; Granular bases; Inflation; Pavement performance; Properties of materials; Shear stress; Strain (Mechanics); Subgrade (Pavements); Tension; Tire pressure; Tires; Trucks
• Old TRIS Terms: Compressive strain; Finite elements
• Subject Areas: Design; Geotechnology; Highways; Materials; Motor Carriers; Pavements; Vehicles and Equipment; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00457700
• Record Type: Publication
• Report/Paper Numbers: FHWA-TX-85-74+345-1
• Contract Numbers: Study 2-9-84-345
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 31 1986 12:00AM