RES2019-12: Utilization of Accelerated Pavement Tester (APT) for New Materials and Pavement Structure Research

Accelerated pavement test (APT) is defined as the controlled application of a prototype wheel loading at the appropriate load to the full-scale pavement structure, which is used to determine the structural responses and performance of the pavement in a short period. Inverted pavement is an unconventional type of flexible pavement structure. In this pavement structure, an unbound aggregate base (UAB) with a low initial modulus is layered between two stiffer layers, an asphalt concrete layer (AC) and a cement-treated base layer (CTB). This project presents two rounds of APT tests on full-scale inverted pavements. In the first-round APT, a comparison study on the rutting performance between the conventional and inverted pavement structures was presented. In addition, the inverted pavements with different thicknesses of UAB and CTB were studied. Significant permanent deflections were observed in all three pavement lanes after 100k passes of APT. Based on the measured deformation, the inverted pavement structure outperformed the conventional pavement in terms of the final surface deformation. And the inverted pavement with a thicker CTB layer had a better performance than the inverted pavement with a thicker UAB layer. Based on the overall pavement conditions, the inverted pavement can be regarded as an alternative to the conventional flexible pavement, and asphalt mixture layer thickness can be reduced during construction. In the second round of APT, the effect of geogrids in the inverted pavement was investigated. The polypropylene geogrids were installed in the full-scale inverted pavements and different locations of geogrids were discussed as well. After 150k passes of APT, the rutting performance was compared and studied. The results show that the geogrids could improve the rutting resistance of the inverted pavement, but the effect of geogrids depended on the location in the UAB layer. In this study, the geogrids placed at the upper 1/3 upper layer of UAB displayed the best rutting performance among the three pavement lanes due to its constraint for the aggregates. However, when the geogrids were installed at the 2/3 thickness of the UAB, the rutting performance of the inverted pavement structure became worse since its position experienced little tension and could not take effect. Therefore, the location of geogrids plays a vital role in improving the rutting resistance of the inverted pavement.


  • English


  • Status: Completed
  • Funding: $199998
  • Contract Numbers:


  • Sponsor Organizations:

    Tennessee Department of Transportation

    James K. Polk Building
    Fifth and Deaderick Street
    Nashville, TN  United States  37243-0349
  • Managing Organizations:

    Tennessee Department of Transportation

    James K. Polk Building
    Fifth and Deaderick Street
    Nashville, TN  United States  37243-0349
  • Project Managers:

    Woods, Mark

  • Performing Organizations:

    University of Tennessee, Knoxville

    Knoxville, TN  United States 
  • Principal Investigators:

    Huang, Baoshan

  • Start Date: 20181201
  • Expected Completion Date: 20220831
  • Actual Completion Date: 0
  • USDOT Program: Transportation, Planning, Research, and Development

Subject/Index Terms

Filing Info

  • Accession Number: 01771484
  • Record Type: Research project
  • Source Agency: Tennessee Department of Transportation
  • Contract Numbers: RES2019-12
  • Files: RIP, STATEDOT
  • Created Date: May 11 2021 5:00PM