Characterization of Reclaimed Asphalt Pavement (RAP) for HMA Surface Courses in Massachusetts

The goal of this study was to understand the properties of the reclaimed asphalt pavement (RAP) sources available in Massachusetts and develop guidelines or recommendations for using RAP in new hot-mix asphalt surface course mixtures. Massachusetts Department of Transportation (MassDOT) specifications allow up to 15% RAP by dry weight in surface mixtures without using a softer-grade virgin binder or using blending equations to determine the appropriate virgin binder grade. RAPs from 13 sources located geographically across the state were tested to determine important properties such as binder content, recovered RAP binder grade, and maximum theoretical specific gravity. The typically specified PG 64-28 asphalt binder used in the state was obtained from regional suppliers of this grade and tested to confirm the performance grade. Analyses were conducted to evaluate each recommended RAP specification method, and accuracies of these methods were investigated by evaluating the performances of actual mixtures incorporating different RAPs and virgin binder sources. The MassDOT specification allowing up to 15% RAP by dry weight of mixture was found to be not valid and, in many cases, not stringent enough. The findings supported that a specification change is warranted. It is suggested that these changes include requiring testing of critical RAP and virgin binder properties for all mixtures; utilization of blending chart equations to estimate blended binder properties; and subsequent mixture performance testing to ensure adequate performance.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Maps; Photos; References; Tables;
  • Pagination: 99p

Subject/Index Terms

Filing Info

  • Accession Number: 01751617
  • Record Type: Publication
  • Report/Paper Numbers: 20-013
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Sep 1 2020 1:44PM