Binder Availability in Recycled Materials: Review of Literature and Available Quantification Methods

Increasing recycled material content in asphalt mixtures provides economic and environmental benefits, but each unique material combination of virgin and recycled materials and additives must be engineered to ensure adequate performance with proper selection of component materials and balanced proportioning, as well as 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. This synthesis project addressed these issues by reviewing the literature available on the topic of recycled binder availability, collecting information on the state of the practice regarding recycled binder availability, performing a detailed analysis on three different recycled binder availability quantification methods, and revising the Texas Department of Transportation balanced mix design spreadsheet for Superpave mixtures to incorporate recycled binder availability.

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• Summary URL:
  https://static.tti.tamu.edu/tti.tamu.edu/documents/0-7062-PSR.pdf
• Summary URL:
  https://library.ctr.utexas.edu/Presto/catalogid=39681
• Summary URL:
  https://library.ctr.utexas.edu/Presto/catalogid=39682
• Record URL:
  https://static.tti.tamu.edu/tti.tamu.edu/documents/0-7062-R1B.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/59222
• Corporate Authors:

  Texas A&M Transportation Institute

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

  Texas Department of Transportation

  Research and Technology Implementation Office
  125 E 11th Street
  Austin, TX  United States  78701-2483

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Martin, Amy Epps
  • Mercado, Edith Arámbula
  • Abdelaziz, Amal
• Publication Date: 2021-10

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Technical Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 72p

Subject/Index Terms

• TRT Terms: Binder content; Mix design; Recycled materials; Superpave
• Identifier Terms: Texas Department of Transportation
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01789197
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-21/0-7062-R1B, 0-7062-R1B
• Contract Numbers: Project 0-7062
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Nov 22 2021 11:31AM