Evaluation of Structural Integrity for a Foamed Asphalt Base Course Using 100% Reclaimed Asphalt Pavement

In recent years, the use of Reclaimed Asphalt Pavement (RAP) is becoming more common for asphalt pavement construction and maintenance, primarily because of the economic and environmental benefits. However, despite Georgia Department of Transportation’s extensive use of RAP in its asphaltic concrete mixtures, thousands of tons of RAP continue to accumulate in contractors’ asphalt plant stockpiles located in the urban areas around the state. The primary goal of this study was to evaluate the structural integrity of 100% recycled asphalt mixtures using a foamed asphalt technology to determine whether these mixtures can effectively be used to replace conventional bound and unbound base courses. The results of this study indicate that the structural layer coefficients of 100% recycled foamed asphalt mixtures ranged from 0.22-0.27, based upon the Marshall Stability test and following the recommendations provided in the 1993 AASHTO Guide for Design of Pavement Structures. When a rejuvenator was added to the mixture, the mixture stiffness decreased considerably, which dropped the structural layer coefficients to 0.16-0.18 at a 6% rejuvenator dosage. There were further reductions in stability as more rejuvenator was added. According to Wirtgen’s nomograph for 100% recycled asphalt mixtures, the coefficients were estimated to be over 0.35 when a dry ITS was used for the coefficient estimation for no-rejuvenator mixtures. At a 6% rejuvenator dosage, the coefficients ranged from 0.24-0.30. Based on the performance test results conducted in the laboratory, a 100% recycled foamed asphalt mixture appears suitable for use as a base course in pavement systems in Georgia, replacing the current base courses.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 108p

Subject/Index Terms

Filing Info

  • Accession Number: 01689087
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-GA-18-1632, RP 16-32
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Dec 7 2018 3:12PM