Development of laboratory mix design procedures for RAP mixes.

Details

• Creators:
  Cooley, Jr., L. Allen ; Williams, Kevin
• Corporate Creators:
  Burns Cooley Dennis, Inc.
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  Asphalt Pavements Binders Blending Hot Mix Paving Mixtures Laboratory Tests Mix Design Recycled Materials Stiffness
• Publication/ Report Number:
  FHWA/MS-DOT-RD-13-246 ; MS-DOT-RD-13-246
• Resource Type:
  Tech Report
• Geographical Coverage:
  Mississippi
• Corporate Publisher:
  Mississippi. Dept. of Transportation
• Abstract:
  The objective of this study was to evaluate the amount of blending that occurs between RAP and virgin asphalt
  
  binders in plant produced HMA in which RAP is incorporated. This objective was accomplished by testing plant
  
  produced mixture from three different on-going HMA projects. Two of the three projects incorporated 15 percent
  
  RAP while the third project incorporated 30 percent. Samples were brought back to the laboratory and subjected
  
  to a staged extraction/recovery process. Asphalt binder recovered from each stage was subjected to Dynamic
  
  Shear Rheometer testing in order to determine the high failure temperature using a criterion of 2.20 kPa.
  
  Based upon the research approach, it was concluded that majority of asphalt binder was extracted and recovered
  
  from the first stage of washing. The amount of asphalt binder extracted/recovered from successive washes
  
  decreased, except for the last stage. For mixes containing 15 percent RAP, the asphalt binder was not significantly
  
  affected by the RAP though there was a slight increase in failure temperature through the staged washes, except
  
  for the last stage. The majority of the asphalt binder from the 30 percent RAP mixture was removed during the
  
  first stage of washing. The stiffness of the asphalt binder after Wash 1 was higher for this 30 percent RAP mix
  
  than for the 15 percent RAP mix; however, the increase in stiffness was not large. The increase in stiffness for
  
  successive washes was higher for the 30 percent RAP mix than for the 15 percent RAP mixes. Based upon these
  
  findings, it was concluded that partial blending between RAP and virgin asphalt binders when RAP is
  
  incorporated into plant produced HMA.
  
  
• Format:
  PDF
• Funding:
  State Study No. 246 ; Project No. SPR-1(60) 106266 166000
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:4cda9ca85971360299700526f6fa7f216ddd248c6e292e6bafde9398ebf9d7d2
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27481/dot_27481_DS1.pdf
• File Type:
  [PDF - 581.34 KB ]