Determination of usable residual asphalt binder in RAP.

Details

• Creators:
  Al-Qadi, Imad L. ; Carpenter, Samuel H. ; Roberts, Geoff ; Ozer, Hasan ; Aurangzeb, Qazi
• Corporate Creators:
  University of Illinois at Urbana-Champaign ; Louisiana State University (Baton Rouge, La.) ; Illinois. Dept. of Transportation
• Corporate Contributors:
  University of Illinois at Urbana-Champaign. Department of Civil and Environmental Engineering ; Illinois. Department of Transportation. Bureau of Materials and Physical Research ; Illinois Center for Transportation
• Subject/TRT Terms:
  • Pavement design
  • Pavement components
  • Asphalt mixtures Pavements
  • Pavements, Asphalt
• Publication/ Report Number:
  FHWA-ICT-09-031;ICT-09-031, UILU-ENG-2009-2001
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  For current recycled mix designs, the Illinois Department of Transportation (IDOT) assumes 100% contribution of ; working binder from Recycled Asphalt Pavement (RAP) materials when added to Hot Mix Asphalt (HMA). However, it is ; unclear if this assumption is correct and whether some binder may potentially be acting as “black rock,” and not ; participating in the blending process with the new binder. Furthermore, it is also unclear whether binder modifications ; should be considered in the mix design for recycled HMA. The goal of this research was to determine if the current IDOT ; mix design practice required modification with respect to the use of RAP. ; A set of mixtures was prepared using RAP in accordance with current practice. Additional sets were prepared ; using recovered binder and recovered aggregate to simulate the effect of RAP binder blending with virgin binder. Mixes ; containing 0, 20, and 40%RAP were prepared and the dynamic modulus testing results of these mixtures were compared to ; illustrate the effect of RAP on HMA. Tests on recovered, virgin, and blended binders were also conducted using the ; Dynamic Shear rheometer (DSR). ; This study found that up to 20% RAP in HMA does not require a change in binder grade. However, at 40% RAP in ; HMA, a binder grade bump at high temperature and possibly at low temperature is needed; more tests are required to verify ; the need for low temperature binder grade bumping. In addition, this study recommends RAP fractionation in the ; preparation of laboratory specimens.
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• Format:
  PDF
• Funding:
  ICT-R27-11
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16708/dot_16708_DS1.pdf
• File Type:
  [PDF - 4.96 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:d852d97aaa318f822a78948aacf8f57a73aaac95eed0158dde839fe7e0287f405271040a0101b0da599f263c1b131bbc547e76f26aa5ee7c257c1cdd3e5ecc2f