Determining asphalt content for recycled asphalt pavement (RAP) materials.

Details

• Creators:
  Thompson, Gary
• Corporate Creators:
  Oregon. Dept. of Transportation. Research Unit
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Recycled materials
  • Asphalt pavements
  • Recycled asphalt pavements
• Publication/ Report Number:
  FHWA-OR-DF-04-02
• Resource Type:
  Tech Report
• Geographical Coverage:
  Oregon
• Corporate Publisher:
  Oregon. Dept. of Transportation. Research Unit
• Abstract:
  The State of Oregon uses significant amounts of Recycled Asphalt Pavement (RAP) in dense-graded mixes on State ; highways. The design process for these mixes relies on accurately knowing the amount of asphalt cement in the RAP ; materials being used. Beginning in 1997 ODOT began using ignition furnaces to determine RAP asphalt contents and ; gradations. ; Asphalt contents are determined by measuring the change in mass between the original dry RAP sample and the mass of the ; final residue aggregate sample after the asphalt is burned off in the ignition furnace. One shortcoming of the process is that ; a small portion of the aggregate is usually lost in the burning process. The amount of aggregate lost is on the order of 0.5% ; which may be considered significant for most RAP mixtures. ; This research attempted to use volumetric equations to solve for the RAP asphalt content by exploiting the constant nature ; of the Effective Specific Gravity of Aggregates, Gse. A solution is presented using a simplified equation which ignores the ; difference in Specific Gravity of Asphalt, Gb, between the RAP asphalt and the new added asphalt. This solution proved to ; be unstable and diverged significantly with only small changes in assumed Gb. ; A second more exact equation was derived to better account for the difference in Gb between the RAP asphalt and the new ; added asphalt. However, it’s analytic solution collapsed to zero due to the dependent nature of the volumetric equation ; being used. Attempts to derive a second linearly independent equation failed; however, future research may lead to a ; complete solution to this equation.
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• Format:
  PDF
• Funding:
  304-221
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/22813/dot_22813_DS1.pdf
• File Type:
  [PDF - 293.81 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:2ccc8e10950e72f2e0545e1f5f855fe0ded89ef0d6fef4c60e4eab07fde06e288de2d9c7add6c5c9da3d30b53f78104b1de9cf24f968561cf3434e63c4a334dd