Evaluating impact of Recycling Agents (RAs) Introduction Method on Performance of High Reclaimed Asphalt Pavement (RAP) Mixtures at Asphalt Plants

Reclaimed asphalt pavement (RAP) may offer significant cost and other benefits. However, RAP usage has plateaued because of concerns about premature pavement failures linked to stiff recycled binders. Recycling agents (RAs) can improve the activation and performance of aged binders, but their effectiveness depends heavily on how they are introduced—either pre-blended with virgin binder or directly applied to RAP (pretreatment). While laboratory evaluations suggest potential benefits, the real-world impact of these methods remains unclear, limiting RA adoption and RAP utilization. There is a need to assess how RA introduction methods affect high RAP mixtures under actual plant production and field conditions, accounting for variables such as binder diffusion, RAP conditioning time, and plant process parameters. The objective of this research is to evaluate and compare the effectiveness of RA pre-blending and pretreatment methods for high RAP mixtures in plant production settings, using laboratory and field performance data to inform practical implementation strategies.

• Record URL:
  • http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5850
• Supplemental Notes:
  • Contract to a Performing Organization has not yet been awarded.

Language

• English

Project

• Status: Proposed
• Funding: $650,000.00
• Contract Numbers:

  Project 09-75

• 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
• Project Managers:

  Khosravifar, Sadaf

• Start Date: 20250526
• Expected Completion Date: 0
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Blending; Mix design; Production; Reclaimed asphalt pavements; Recycled materials
• Subject Areas: Construction; Highways; Materials; Pavements;

Filing Info

• Accession Number: 01956440
• Record Type: Research project
• Source Agency: Transportation Research Board
• Contract Numbers: Project 09-75
• Files: TRB, RIP
• Created Date: May 28 2025 10:09AM