Investigating Asphalt Mix Design Using Reclaimed Asphalt Shingles (RAS)

Reclaimed Asphalt Shingles (RAS) are being incorporated into asphalt mixes at historic rates in North America. Some suggest that a portion of the asphalt binder from RAS should not be counted as binder in the asphalt mix design. AASHTO PP53-09 includes a method to determine a RAS asphalt binder availability factor. This factor purports to quantify the percentage of RAS binder that contributes to performance of the mix, however is actually dependent on the non-bituminous components of the asphalt shingles. As such, the availability factor is considered to be inappropriate for use. This paper evaluates the effect of RAS on volumetric properties of asphalt mixes to better quantify the availability of asphalt binder from the shingles. An HMA mix was designed using the same percentage of RAS with the asphalt content of the RAS artificially altered using partial extraction. Volumetric properties and asphalt binder availability were determined according to AASHTO PP53-09. The experiment was repeated using shingles from three sources. Results indicate that VMA increased as a result of the shingle addition. The VMA increase was independent of the shingle asphalt binder percentage. As a result asphalt binder availability factors calculated according to AASHTO PP53-09 are highly variable and non-intuitive. (A) For the covering abstract of this conference see ITRD record number 201402RT334E.

Language

  • English

Media Info

  • Pagination: p. 403-18
  • Monograph Title: Proceedings of the Fifty-Eighth Annual Conference of the Canadian Technical Asphalt Associatio (CTAA): St. John's, Newfoundland and Labrador, November 2013

Subject/Index Terms

Filing Info

  • Accession Number: 01518100
  • Record Type: Publication
  • Source Agency: Transportation Association of Canada (TAC)
  • Files: ITRD, TAC
  • Created Date: Mar 11 2014 11:01AM