Capturing Durability of High Recycled Binder Ratio (RBR) Asphalt Mixtures

Environmental sustainability and economic benefits motivate maximum use of recycled asphalt materials (RAM), including reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS), in asphalt mixtures. However, when stiff, brittle, aged materials are added to virgin asphalt-aggregate mixtures, adequate durability (initially and with time) must be maintained by engineering each unique combination of virgin and recycled materials. To maximize durability, state departments of transportation (DOTs) currently limit the RAP and RAS contents and their overall recycled binder ratio (RBR). Strategies for improving binder rheology and mixture durability include utilizing a softer base binder or adding a recycling agent (rejuvenator), but the durability of mixtures utilizing these strategies is unknown. The objectives of this research were: (1) produce a proposed AASHTO standard practice and associated test methods for design and evaluation of durable high RAM content asphalt mixtures and (2) revise the proposed AASHTO Standard Practice for Characterization of Asphalt Mixtures with High Recycled Materials Contents and Recycling Agents produced in NCHRP Project 09-58 to address mixture durability.

• Record URL:
  http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=4960
• Supplemental Notes:
  • Research completed. Publication decision pending.

Language

• English

Project

• Status: Completed
• Funding: $750000
• Contract Numbers:

  Project 09-65

• 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:

  Barcena, Roberto

• Performing Organizations:

  Texas A&M Transportation Institute (TTI)

  400 Harvey Mitchell Parkway South
  Suite 300
  College Station, TX  United States  77845-4375
• Principal Investigators:

  Martin, Amy

• Start Date: 20210326
• Expected Completion Date: 20240630
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Aging (Materials); Asphalt mixtures; Binders; Cracking; Durability; Recycled materials
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01739634
• Record Type: Research project
• Source Agency: Transportation Research Board
• Contract Numbers: Project 09-65
• Files: TRB, RIP
• Created Date: May 20 2020 9:23AM