Characterization of Different RAP Sources

Details

• Creators:
  Khosla, N Paul ; Ramoju, Srikanth Sree
• Corporate Creators:
  North Carolina State University. Department of Civil Engineering
• Corporate Contributors:
  North Carolina Department of Transportation. Research and Development Unit ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Binders Blending Blending Charts Complex Shear Modulus Dynamic Shear Rheometer Hot Mix Asphalt Mix Design Phase Angle Reclaimed Asphalt Pavements Regions Rheological Properties Rheometers Shear Modulus Specifications Statistical Analysis Variability

  More +
• Publication/ Report Number:
  FHWA/NC/2014-05
• Resource Type:
  Tech Report
• Geographical Coverage:
  North Carolina ; United States
• Edition:
  Final Report, 2014-2016
• Corporate Publisher:
  North Carolina Department of Transportation. Research and Development Unit
• Abstract:
  Recycling of asphalt pavements is crucial to alleviating the growing demand for paving materials including both asphalt binder and aggregates. For this reason many states have adopted specifications for the use of reclaimed asphalt pavement (RAP) in hot mix asphalt (HMA). These specifications, however, are based on the percentage weight of RAP in the total mix. Because RAP binder is usually much stiffer than virgin binders and contributes largely to the increased stiffness of the recycled mixture placing emphasis on the recycled binder content would be a more efficient way to optimize use of RAP. The state of North Carolina studied recycled materials with the objective of placing limits on percentage of binder contributed by RAP, instead of percentage by weight of mix replaced. As part of the research, one RAP material was selected and tested with different virgin binders and limits were derived. Since, recycled binders from different RAP sources exhibit different properties, the limits determined for binder from a single RAP source are not directly applicable to all RAP sources. This research aimed to evaluate the effect of variability in the RAP binders on the recycled binder limits by examining extensively the rheological properties of recycled binders from different RAP sources. RAP stockpiles from different geographical regions were selected and the recycled binder extracted from RAP was characterized using the Dynamic Shear Rheometer and binder limits determined to identify differences among the stockpiles. Statistical inferences were derived from the rheological properties of the different RAP binders and the binder limits obtained for different stockpiles were used to develop draft specifications to select the optimum amount of recycled materials based on the variability between and within stockpiles.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:80e2ff68678b3f383134dd32ce8d346630b540eea4f3108b55757cbc554f60b1
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/64557/dot_64557_DS1.pdf
• File Type:
  [PDF - 3.64 MB ]