The Importance of Tack Coats and Interlayer Bond Strengths

This article explores the importance of tack coats, also called bond coats, which function as bonding agents between each layer of a pavement section to form the whole asphalt pavement thickness. The author notes that a 2016 FHWA TechBrief defines a tack coat as a sprayed application of asphalt material upon an existing asphalt or Portland cement concrete (PCC) pavement prior to an overlay. Tack coats can also be used between layers of new asphalt concrete. The author discusses bond strength measurement via direct (linear) shear; bond strength measurement via tension; and interlayer bond strength evaluation. The article also reports the findings of a recent survey that asked state departments of transportation (DOTs) about their practices regarding interface bond strength testing. Four different testers are illustrated.


  • English

Media Info

  • Media Type: Print
  • Features: Figures; Photos;
  • Pagination: pp 7-12
  • Serial:
    • Asphalt
    • Volume: 33
    • Issue Number: 1
    • Publisher: Asphalt Institute
    • ISSN: 0004-4954

Subject/Index Terms

Filing Info

  • Accession Number: 01675866
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 8 2018 6:38AM