Synthesis for Quantification of Binder Availability in Recycled Materials

Increasing recycled materials content in asphalt mixtures provides economic and environmental benefits, but each unique materials combination of virgin and recycled materials and additives must be engineered to ensure adequate performance with proper selection of component materials, balanced proportioning, and consideration of recycled binder availability. The design of mixtures with recycled materials often assumes that 100 percent of the recycled binder is available to blend with the virgin binder, and the virgin binder content is reduced accordingly. In reality, when recycled binder availability is less than 100 percent for heavily aged materials, total binder contents are less than optimum from mix design, resulting in dry mixtures with insufficient coating and inadequate durability and cracking performance. In addition, recycled binder availability can be used to assess aging state and preclude the use of large quantities of these materials with stiff, brittle binders that contribute negatively to performance even if available. The Performing Agency will address these concerns and revise TxDOT’s Standard and/or Special Specifications to incorporate recycled binder availability as part of mix design and revise the allowable maximum recycled binder ratio (RBR) limits as appropriate in a synthesis project based only on literature and available data.

• Record URL:
  https://library.ctr.utexas.edu/Presto/project=0-7062

Language

• English

Project

• Status: Completed
• Funding: $64988
• Contract Numbers:

  0-7062

• Sponsor Organizations:

  Texas Department of Transportation

  125 E. 11th Street
  Austin, TX  United States  78701-2483

  Federal Highway Administration

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

  Texas Department of Transportation

  125 E. 11th Street
  Austin, TX  United States  78701-2483
• Project Managers:

  Glancy, Chris

• Performing Organizations:

  Texas Transportation Institute

  Texas A&M University System
  3135 TAMU
  College Station, TX  United States  77843-3135
• Principal Investigators:

  Martin, Amy Epps

• Start Date: 20191101
• Expected Completion Date: 20201031
• Actual Completion Date: 20201031

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Binder content; Mix design; Recycled materials
• Subject Areas: Construction; Materials;

Filing Info

• Accession Number: 01744096
• Record Type: Research project
• Source Agency: Texas Department of Transportation
• Contract Numbers: 0-7062
• Files: RIP, STATEDOT
• Created Date: Jun 25 2020 3:57PM