Evaluating the Performance of Inverted Pavements in Tennessee

Reflective cracking is a primary issue on composite pavements with a cement-treated base (CTB) and an asphalt surface layer. Numerous studies have indicated that the CTB is prone to shrinkage cracking, which often propagates upwards into the asphalt surface layer and causes the reflective cracking (Eltahan and Lytton, 2000; Rasoulian et al., 2000; Sousa et al., 2002; Titi et al., 2003). The maintenance of reflective cracking is very difficult, as it is related both to material defects and structural deficiency (Eltahan and Lytton, 2000; Pickett and Lytton, 1983). A demonstrated effective approach for addressing the reflective cracking is using inverted pavements. An inverted pavement, opposite to the conventional flexible pavement with CTB overlaying the unbound aggregate base, is constructed with a cement-treated sub-base underlying an unbound aggregate base (Barksdale and Todres, 1983; Rasoulian et al., 2000; Tutumluer and Barksdale, 1995). The concept of inverted pavement was developed in South Africa in the 1970s, and many effective applications have been reported in Georgia (Terrell et al., 2003), Louisiana (Titi et al., 2003), Mississippi (Barker et al., 1973), among others. In the inverted pavement design, an unbound aggregate layer, which is usually used as a subbase beneath the stabilized base, is sandwiched between the asphalt surface layer and the cement stabilized base. The reason for the unique location of the unbound base in an inverted pavement is that unbound aggregate is a highly stress-dependent material. When placed closer to the pavement surface, the unbound aggregates will be subjected to a higher stress state, resulting in a higher stiffness of the unbound aggregate layer and thus a better pavement performance. Compared to conventional flexible pavements, an inverted pavement has the following benefits: Significant cost savings due to a relatively thin asphalt surface layer; High rut resistance; Reduced transverse cracking; High traffic volume capacity; Reduced energy consumption; Longer service life. TDOT has long been trying to evaluate and adopt this technology due to its significant cost benefits. In the past several years, TDOT wanted to use the inverted pavement on more than three projects. However, each time the push has not gone beyond letting stage due to lack of confidence. This proposed research project will continue TDOT’s effort to apply this technology in Tennessee. Once successful, the research will bring/build the confidence that TDOT needs to implement this innovative technology.

    Language

    • English

    Project

    • Status: Active
    • Funding: $159,141.00
    • Contract Numbers:

      RES2020-12

      40100-07219

    • 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:

      Jonas-Fields, Stephanie

    • Performing Organizations:

      University of Tennessee, Knoxville

      Knoxville, TN  United States 
    • Principal Investigators:

      Huang, Baoshan

    • Start Date: 20200101
    • Expected Completion Date: 20201130
    • Actual Completion Date: 0
    • USDOT Program: Transportation, Planning, Research, and Development

    Subject/Index Terms

    Filing Info

    • Accession Number: 01744244
    • Record Type: Research project
    • Source Agency: Tennessee Department of Transportation
    • Contract Numbers: RES2020-12, 40100-07219
    • Files: RiP, STATEDOT
    • Created Date: Jun 26 2020 5:48PM