Comparative Analysis of Tack Coat, Underseal Membrane, and Underseal Technologies

Several options are available for preparing a surface prior to an asphalt overlay. These include traditional tack coats, non-tracking tack coats, thicker spray-applied underseal membranes, and traditional underseals. Tack coats, with a shot rate between 0.04 and 0.14 gallon (gal)/square yard (sy), are expected to provide better bonding. Underseal membranes (0.13 – 0.3 gal/sy) and underseals (>0.3 gal/sy with rock) are expected to reduce moisture infiltration and reflective cracking. However, these benefits have not been sufficiently quantified, and neither has the overall impact on the asphalt overlay service life. Some of these approaches can have considerably higher costs of materials and equipment. Currently, it is unknown whether the added benefits of these technologies (potentially longer service life) result in cost savings to Texas Department of Transportation (TxDOT). The objective of this study is to evaluate the performance of asphalt overlays achieved with different tacking and sealing technologies, namely: Traditional tack coats, Non-tracking tack coats, Underseal membranes from a spray-paver, and Traditional underseals. In the work plan, the research team shall evaluate each technology with respect to: (1) Layer bonding, (2) Sealing against moisture, (3) Resistance to reflection cracking, and (4) General overlay condition.


  • English


  • Status: Completed
  • Funding: $417,803
  • Contract Numbers:


  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Glancy, Chris

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Wilson, Bryan

  • Start Date: 20160101
  • Expected Completion Date: 20180630
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01618977
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-6908
  • Files: RiP, STATEDOT
  • Created Date: Dec 20 2016 4:44PM