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Mid-America Transportation Center

Performance Measures of Warm Asphalt Mixtures for Safe and Reliable Freight Transportation

Final Report
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University of Iowa

Transportation Systems Engineering


  • Principal Investigator: Hosin Lee ( 319-335-6818)
  • Graduate Students
  • Nishant Sheth
  • Jeremy Purvis
  • Anand Sampath
  • Project Status
  • Start Date: 3/10/2008
  • End Date: 12/31/2009
  • Sponsors & Partners
  • Mid-America Transportation Center
  • University of Iowa
  • About this Project
    Brief Project Description & Background
    Four types of asphalt mixtures (OGFC, SMA, WMA and HRA) will be evaluated with respect to their mix design procedures, dynamic creep and frictional characteristics.
    Research Objective
    The safe and reliable WMA and HRA mixtures will contribute to the road safety by reducing the number of crashes and fatalities on heavy roadway system and minimize risk associated with increasing freight movements on the U.S. surface transportation system.
    Potential Benefits
    The main product anticipated from this research is the evaluation result of WMA and HRA with respect to their rutting and moisture susceptibility and frictional characteristics. This information would be very useful for all pavement engineers, who are interested in WMA and HRA for application.
    Warm mix asphalt (WMA) is an emerging technology that can allow asphalt to flow at a lower temperature for mixing, placing and compaction. The advantages of WMA include reduced fuel consumption, less carbon dioxide emission, longer paving season, longer hauling distance, reduced oxidation of asphalt, early opening to traffic and a better working environment in the field. In the United States, WMA has become popular in recent years. However, to provide a safe and reliable highway for heavier truck traffic with a high tire pressure, WMA mixtures must meet requirements for strength, stiffness, rutting and moisture resistance. WMA mixtures with six commercially available WMA additives, which include CECABASE RT®, Sasobit®, Aspha-min®, Advera WMA, Evotherm J1, and RedisetTM WMX, along with the control WMA mixture without any additive and the control HMA mixture, were evaluated for their air voids, indirect tensile strengths and moisture susceptibilities. To evaluate a long-term reliable performance over a wide range of traffic and climatic conditions, the dynamic modulus and the repeated load tests were conducted on these mixtures using the simple performance testing equipment. Based on the limited test results, Sasobit®, Evotherm J1 and RedisetTM WMX were effective in producing WMA mixtures in the laboratory that is comparable to HMA mixtures.
    Total Project Cost
    $ 50,000
    Modal Orientation
  • Concrete and Pavements