The Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP Binder Ratios

The objectives of this research are to (1) evaluate the effectiveness of recycling agents in hot mix asphalt (HMA) and warm mix asphalt (WMA) mixtures with high recycled asphalt shingles (RAS), reclaimed asphalt pavement (RAP), or combined RAS/RAP binder ratios through a coordinated program of laboratory and field experiments; (2) propose revisions to several relevant AASHTO specifications and test methods; and (3) develop training and workshop materials and deliver one workshop. Since current practice generally limits recycled binder ratios to 0.3 or less, the scope of this research shall encompass asphalt mixtures prepared with recycling agents and RAS, RAP, or combined RAS/RAP at recycled binder ratios between 0.3 and 0.5. The performance of binders and mixtures containing recycling agents shall be compared to that of equivalent binders and mixtures (1) without recycling agents and (2) without RAS and RAP. It is anticipated that the majority of mixture testing in this research will be conducted on plant-mixed, laboratory-compacted (PMLC) specimens obtained from trial batches or production runs prepared in asphalt mix plants. Consistent laboratory conditioning procedures shall be applied to all specimens and changes in mixture properties with aging in the field shall be quantified. Field test sections shall be documented such that long-term performance studies can be conducted with these sections in future NCHRP research projects.


  • English


  • Status: Completed
  • Funding: $1500000
  • Contract Numbers:

    Project 09-58

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Performing Organizations:

    Texas A&M Transportation Institute

  • Principal Investigators:

    Martin, Amy

  • Start Date: 20140502
  • Expected Completion Date: 20181130
  • Actual Completion Date: 20181130

Subject/Index Terms

Filing Info

  • Accession Number: 01735309
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 09-58
  • Files: TRB, RIP
  • Created Date: Mar 30 2020 5:11PM