Asphalt Rubber Technology Information Center
Assessment of Warm Mix Technologies for Use with Asphalt Rubber Paving Applications
R. Gary Hicks, Ding Cheng, and Tyson Teesdale
May, 2010
Warm Mix
Key Words:
Warm Mix, Asphalt Rubber, Pavement Materials
Warm mix asphalt (WMA) is the name given to certain technologies that reduce the production and placement
temperatures of asphalt mixes.  Generally, the placement temperatures should be between 185°F and 275°F for an
asphalt to be considered warm mix asphalt. In the United States, WMA is a relatively new technology; however, Europe
has been at the forefront of WMA technologies since the mid 1990’s.  This report is to evaluate whether there are any
benefits of using warm mix technologies with Asphalt Rubber (AR) chip seals and hot mixes. The potential savings in
energy and reduction in Green House Gas emissions could be great.  The report includes a literature review and a
survey of users of Warm Mix in the United States. It concentrates the research on the use of warm mix technologies with
asphalt rubber in California including, Route 152 near Santa Clara, Interstate 5 near Santa Nella, Interstate 5 near Orland,
CA-94 in San Diego, SR-101 in Fortuna, SR-70 in Marysville, SH 99 in Sutter County, and the Heavy Vehicle Simulator
(HVS) study at a service road at the Granite Rock Company’s A.R. Wilson Quarry by the University of California
Pavement Research Center.

The overall field testing and research results demonstrate that there are a wide range of benefits which can be attained
by using warm mix technology in rubberized asphalt mixes. These may include reduced fuel usage and emissions,
compaction aid, longer paving season, night paving, long hauling distances, and improved working conditions.  In the
future, additional study needs to be done on warm mix technologies with asphalt rubber and terminal blend chip seals,
moisture susceptibility of rubberized warm mix asphalts, and evaluation of new warm mix innovations used in
rubberized asphalt concrete.
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