Structural improvement using SBS-modified binders

The most popular bitumen modifier styrene-butadiene-styrene block-copolymer (SBS) does not have a great effect on the stiffness of the binder and thus the asphalt mix. From that perspective, it would not have a big impact on the design of a pavement, particularly if the design method does not take into account resilience and fatigue performance improvement. At the same time, modifying hard base bitumen is not obvious from a compatibility and workability perspective with the standard SBS polymers available, while there is a regional trend in the industry to use increasingly harder binders that increase the stiffness. One example is the use of the French EME concept in which specially prepared bitumen is used of 20/30 or even 10/20 penetration. These mixes need to comply with stringent requirements on stiffness and fatigue resistance, which sometimes leads to long mix design procedures, which are required every time other aggregate sources are used. However, through the development of a new SBS type of polymer, it is now also possible to modify hard bitumen at such a level that step changes in fatigue and deformation resistance are achieved. These binders can be used in any standard asphalt mix design, not requiring a special high performance aggregate. Through its superior fatigue performance and sufficiently high stiffness, overall pavement thickness reduction can be achieved, as much as 20 – 60%, which makes the road cheaper to apply and which requires less maintenance. This paper will show some of the highlights in performance improvements, the latest results in testing at the National Center for Asphalt Technology (NCAT) in the United States and some basic calculations demonstrating the great value proposition that this new technology offers.

Language

  • English

Media Info

  • Pagination: 7p
  • Monograph Title: 11th Conference on Asphalt Pavements for Southern Africa: CAPSA15, 16-19 August 2015, Sun City, South Africa

Subject/Index Terms

Filing Info

  • Accession Number: 01597158
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Apr 22 2016 11:18AM