Comparative Analysis of Tack Coats, Spray Paver Membranes, and Underseals: Technical Report

Tack coats, trackless tack coats, spray paver underseal membranes, and underseals provide varying levels of bonding and sealing performance, but these benefits have not been sufficiently quantified, and neither has the overall impact on the asphalt overlay service life. This study 1) evaluated the performance of bonding and sealing treatments for bond strength, resistance to reflection cracking, and permeability, 2) estimated the life-cycle cost for each treatment, and 3) provided a reference guide for bonding and sealing treatments. Laboratory samples and field samples from 42 test sections on five overlay projects were tested for bond strength (Texas shear bond strength test), cracking resistance (modified Texas overlay test and compact tension test), and permeability (Florida falling head permeability test). All tests were sensitive to treatment type. Hot-applied trackless tack had the highest bond strength and spray paver membranes and underseals were the weakest, though all treatments demonstrated acceptable performance. Bond strengths varied significantly among the projects. Bonding was very sensitive to sample age with older samples having higher strength. Most of the bond strength is likely gained in the first month. The highest cracking resistance and also the lowest permeability was from high-residual treatments (underseal, spray paver membrane, and hot-applied trackless tack). The performance of an overlay over aged transversely cracked pavement was modeled. Higher bonding increased fatigue and rutting life. For reflection cracking, a partial bond resulted in longer service life. The spray paver membrane and underseal treatments had the longest service life and the spray paver membrane had the lowest life-cycle cost. For other scenarios, constrained by rutting or fatigue, a different treatment is likely to prove more cost-effective. A bonding and sealing treatment guide was developed with scenario recommendations for applying each treatment.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 122p

Subject/Index Terms

Filing Info

  • Accession Number: 01687638
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-18/0-6908-R1, 0-6908-R1
  • Contract Numbers: 0-6908
  • Created Date: Dec 4 2018 10:09AM