Use of Rejuvenator Prior to Chip Seal on Aged Flexible Pavement

Emulsions are used as tack coats to bond hot-mix asphalt layers and in chip seals to bind aggregates. The rate of emulsion application is critical to the performance of both tack coats and chip seals and hence, is an important design factor. Emulsion is often applied to aged flexible pavements in North Carolina. Oxidative aging embrittles asphalt binder near the pavement surface which increases top down cracking and raveling, leaving the pavement surface porous and dry. Consequently, when emulsion is applied to an aged flexible pavement, a portion of the applied emulsion will be absorbed by the existing pavement. To compensate, the current practice is to adjust the required target Emulsion Application Rate (EAR) used in the construction based on visual inspection of the existing pavement surface. This current practice is subjective and visual appearance cannot be tied directly to surface dryness. Therefore, an improved method is needed to inform adjustment of the target EAR during construction to account for emulsion lost to absorption. Improved selection of the design EAR will result in prolonged pavement service life, potentially resulting in significant economic savings. The objectives of the proposed research project are to do the following: (1) Determine the rate by which pavements absorb emulsion as a function of pavement surface characteristics; and (2) Develop guidelines for the adjustment of the target EAR to account for emulsion absorption based on quantitative measurement of the existing pavement surface characteristics.

Language

  • English

Project

  • Status: Active
  • Funding: $258,427
  • Contract Numbers:

    FHWA/NC/2018-15

  • Sponsor Organizations:

    North Carolina Department of Transportation

    Research and Development
    1549 Mail Service Center
    Raleigh, NC  United States  27699-1549
  • Managing Organizations:

    North Carolina Department of Transportation

    Research and Development
    1549 Mail Service Center
    Raleigh, NC  United States  27699-1549
  • Project Managers:

    Bolyard, Steven

  • Performing Organizations:

    North Carolina State University, Raleigh

    Department of Civil Engineering, Campus Box 7908
    Raleigh, NC  United States  27695-7908
  • Principal Investigators:

    Castorena, Cassie

  • Start Date: 20170801
  • Expected Completion Date: 20190731
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01640079
  • Record Type: Research project
  • Source Agency: North Carolina Department of Transportation
  • Contract Numbers: FHWA/NC/2018-15
  • Files: RiP, STATEDOT
  • Created Date: Jun 30 2017 11:29AM