Glass Transition and Thermal Cracking of Modified Asphalt Binders

Thermal cracking is one of the main challenges pavement engineers are faced with in cold regions. One of the unique aspects of this failure is that it relates to asphalt binder properties. It is caused by cooling cycles and the contraction of asphalt materials with decreasing temperatures. It is therefore logical to expect that selecting binders that are stronger, more strain tolerant, or exhibit less contraction with decreasing temperatures can improve resistance to thermal cracking. This paper presents results on glass transition and thermal cracking behaviour for several asphalts produced by two main modification technologies. The results show that by carefully engineering the modification, the coefficients of contraction above and below the glass transition region of binders can be reduced and there can be a significant shift in glass transition temperature relative to pavement temperatures thereby improving the strength and strain tolerance at extreme low pavement temperatures. It is clear that using the Creep Stiffness (S) and the Creep Rate (m), as currently practiced, are not sufficient to evaluate the full effect of modification on thermal cracking behaviour. The results show that engineering binders by refinery processes and using specific additives are viable methods of changing cracking temperatures by adjusting thermal contraction behaviour and by changing failure properties.

Language

  • English

Media Info

  • Media Type: Print
  • Pagination: pp. 103-122.
  • Monograph Title: Proceedings of the Forty-Eighth Annual Conference of the Canadian Technical Asphalt Association (CTAA): Halifax, Nova Scotia, November 2003

Subject/Index Terms

Filing Info

  • Accession Number: 01604982
  • Record Type: Publication
  • Source Agency: Transportation Association of Canada (TAC)
  • Files: ITRD, TAC
  • Created Date: Jul 26 2016 5:02PM