RAP MIX DESIGN FOR HMA PAVEMENTS

This article, the second in a three-part series on the use of reclaimed asphalt pavement (RAP) in hot-mix asphalt (HMA), focuses on RAP mix design techniques. While plant technology and the amount of fines in RAP present practical limitations, it is noted that overly conservative specifications may be the greatest obstacle limiting the use of RAP in HMA. The mix design process, production realities, and performance history should be the limiting factors for the percentage of RAP, not arbitrary specification limits. When the viscosity blending approach was first introduced, the graphical solution to percentage RAP was used for each RAP mix design. However, with years of experience, many mix designers have established rules-of-thumb to minimize the test required. With the introduction of the Superpave performance grade binder specifications, changes are required in the mix design process in order to accommodate the use of RAP. The existing viscosity blending chart approach does not meet the specification requirements of Superpave. The Federal Highway Administration Mixture Expert Task Group has developed a draft list of recommendations for use of RAP in Superpave. Verification activities are under way and should be completed in 1-2 years.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/11660022
• Corporate Authors:

  Scranton Gillette Communications

  380 E Northwest Highway, Suite 200
  Des Planes, IL  United States  60016-2282
• Authors:
  • Decker, D
• Publication Date: 1999-2

Language

• English

Media Info

• Features: Photos;
• Pagination: p. 24-27
• Serial:
  • Roads & Bridges
  • Volume: 37
  • Issue Number: 2
  • Publisher: Scranton Gillette Communications
  • ISSN: 8750-9229
  • Serial URL: http://www.roadsbridges.com/rb/

Subject/Index Terms

• TRT Terms: Asphalt pavements; Blending; Blends; Hot mix asphalt; Mix design; Recycled materials; Recycling; Superpave; Viscosity
• Identifier Terms: U.S. Federal Highway Administration
• Subject Areas: Highways; Materials; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00762844
• Record Type: Publication
• Files: TRIS, ATRI
• Created Date: Apr 27 1999 12:00AM