Interim Report: Binder Rheology and Performance in Warm Mix Asphalt

Since the introduction of warm mix asphalt (WMA) in the United States, a variety of different technologies and processes have been developed and used to achieve proper mixing and compaction at reduced temperatures compared to conventional hot mix asphalt. A better understanding of the effect of WMA additives and reduced aging on rheology of asphalt binders is a crucial step towards the successful implementation of WMA. This report presents the preliminary findings from a study conducted to investigate the influence of chemical WMA additives and reduced aging on the viscosity, stiffness, susceptibility to permanent deformation, fracture resistance, and thermal cracking resistance of asphalt binders. Short-term aged WMA binders have reduced stiffness compared to conventional binders due to the reduced mixing temperatures. However, preliminary results indicate that certain WMA additives tend to exacerbate the reduced stiffness of WMA while other WMA additives tend to compensate for this effect. In most cases, long-term aged WMA binders had a similar stiffness but similar or reduced strength compared to conventional binders at intermediate temperatures. Also, the long-term aged WMA binders had similar or slightly reduced resistance to low-temperature cracking compared to conventional binders. In most cases, the use of WMA with recycled asphalt rendered the asphalt binder slightly more susceptible to low-temperature cracking.

  • Record URL:
  • Supplemental Notes:
    • Project Title: Developing a Fundamental Understanding of the Chemistry of Warm Mix Additive. Report Date: January 2012; Published: August 2012.
  • Corporate Authors:

    University of Texas, Austin

    Center for Transportation Research, 1616 Guadalupe Street
    Austin, TX  United States  78701-1255

    Texas Department of Transportation

    Research and Technology Implementation Office, P.O. Box 5080
    Austin, TX  United States  78763-5080

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Arega, Zelalem
    • Bhasin, Amit
  • Publication Date: 2012-8


  • English

Media Info

  • Media Type: Web
  • Edition: Technical Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 94p

Subject/Index Terms

Filing Info

  • Accession Number: 01446460
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-12/0-6591-2, Report 0-6591-2
  • Contract Numbers: Project 0-6591
  • Created Date: Sep 18 2012 3:56PM