Impact of High RAP Contents on Structural and Performance Properties of Asphalt Mixtures

Currently, highway agencies in Illinois are exploring the feasibility of using higher amounts of reclaimed asphalt pavement (RAP) in asphalt mixtures. Concerns about variability in aggregate gradation and higher stiffness of aged RAP binder have limited this use, however. This research project was designed to characterize the performance of hot-mix asphalt (HMA) with high amounts of RAP and to identify any special considerations that must be met to utilize these higher RAP contents. Two material sources from two districts were used to prepare eight 3/4-in nominal maximum aggregate size (NMAS) N90 binder mix designs. The mix designs included a control mix with 0% RAP and three HMAs with 30%, 40%, and 50% RAP for each district. A base asphalt binder (PG 64-22) was used in the mix design process; a single-bumped binder (PG 58-22) and a double-bumped binder (PG 58-28) were also used to prepare specimens for performance testing. The tests conducted on the HMAs were moisture susceptibility, flow number, complex modulus, beam fatigue, semi-circular bending, and wheel tracking. All tested HMAs with RAP performed equal to or better than the mixtures prepared with virgin aggregate. The study found that HMAs with high RAP content (up to 50%) can be designed with desired volumetrics. RAP fractionation proved to be very effective. Asphalt binder-grade bumping is vital for HMAs with 30% RAP content and above.

• Record URL:
  https://www.ideals.illinois.edu/bitstream/handle/2142/45810/FHWA-ICT-12-002.pdf?sequence=2
• 
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01979191
• Supplemental Notes:
  • Title on cover: Impact of High RAP Content on Structural and Performance Properties of Asphalt Mixtures.
• Corporate Authors:

  University of Illinois, Urbana-Champaign

  Department of Civil and Environmental Engineering
  205 North Mathews Avenue
  Urbana, IL  United States  61801-2352

  Illinois Department of Transportation

  Bureau of Materials and Physical Research
  126 East Ash Street
  Springfield, IL  United States  62704-4766

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Al-Qadi, Imad L
  • Aurangzeb, Qazi
  • Carpenter, Samuel H
  • Pine, William J
  • Trepanier, James
• Publication Date: 2012-6

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; References; Tables;
• Pagination: 108p
• Serial:
  • Civil Engineering Studies, Illinois Center for Transportation Series
  • Issue Number: 12-002
  • Publisher: University of Illinois, Urbana-Champaign
  • ISSN: 0197-9191

Subject/Index Terms

• TRT Terms: Aggregate gradation; Fatigue tests; Fracture tests; Hot mix asphalt; Performance tests; Reclaimed asphalt pavements; Stiffness tests; Volumetric analysis
• Uncontrolled Terms: Moisture susceptibility
• Subject Areas: Highways; Pavements; I22: Design of Pavements, Railways and Guideways; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01447429
• Record Type: Publication
• Report/Paper Numbers: FHWA-ICT-12-002, UILU-ENG-2012-2006
• Contract Numbers: ICT R27-37
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Sep 26 2012 1:26PM