Geogrid Reinforced Aggregate Base Stiffness for Mechanistic Pavement Design

The pavement design package created by Itasca extends the capabilities of Particle Flow Code 3D (PFC3D) to support triaxial testing of a synthetic unsaturated aggregate base containing geogrid. The geogrid provides lateral restraint to the aggregate base as a result of interlocking and friction between the geogrid and the aggregate particles. The macroscopic system properties are affected by the microstructural system properties. Therefore, the modeled system was used to study and quantify the effect of microstructural properties on the macroscopic properties, which include the stress-strain curves produced during triaxial tests at different confinements. The microstructural properties of the aggregate base include: particle size, particle type (density, Young’s modulus, and Poisson’s ratio of each particle; and friction between particles), aggregate base moisture content (suction and gap), and initial aggregate base porosity. The microstructural properties of the geogrid include: geometry (aperture and rib dimensions), Young’s modulus, bond stiffness, and grid-grain interface behavior. The pavement design package provides a mechanistically defensible model for aggregate-geogrid interaction, which was used to improve pavement design by estimating geogrid gain factors for typical geogrid-reinforced aggregate roadways. It is anticipated that a simplified geogrid gain factor adjustment will be trialed during pavement design for projects where geogrid is being considered. As expected, this study concludes that geogrid provides benefit and that this benefit varies during the year. Therefore, it is recommended that the seasonal effects be included during implementation. This would allow the fatigue and rutting to be more accurately estimated over the expected pavement design life.

  • Record URL:
  • Corporate Authors:

    Minnesota Department of Transportation

    Office of Materials and Road Research
    1400 Gervais Avenue
    Maplewood, MN  United States  55109

    Minnesota Department of Transportation

    Research Services and Library
    395 John Ireland Boulevard
    St Paul, MN  United States  55155
  • Authors:
    • Siekmeier, John
    • Casanova, Joseph
  • Publication Date: 2016-7


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; References; Tables;
  • Pagination: 206p

Subject/Index Terms

Filing Info

  • Accession Number: 01610903
  • Record Type: Publication
  • Report/Paper Numbers: MN/RC 2016-24
  • Contract Numbers: (c) LAB4006
  • Created Date: Aug 31 2016 9:16AM