Warm Mix Asphalt on I-70 3-Year Evaluation by CDOT

Mar 22, 2011

The Colorado APA has just announced that “a 3 year evaluation of the use of warm mix asphalt (WMA) on I-70 near Eisenhower Tunnel is complete and the results are very favorable”.  The study conducted by the National Center for Asphalt Technology (NCAT) in cooperation with Colorado Department of Transportation (CDOT)  and the FHWA, concluded that the field performance of the WMA test sections was excellent after three years.

CDOT constructed the test strips in the summer of 2007. The day of the Evotherm paving was almost 20 degrees cooler than the other warm mix additives with comparable roadway densities.  Laboratory performance testing of all the WMA test mixes was similar to the HMA control mix. The study was intended to address early concerns of moisture susceptibility and rutting as well as extending the paving season.  Now, after three years of field evaluations, the performance of the WMA test sections was equal to the HMA control sections in regards to rutting, cracking, and raveling. The field performance was excellent even in this very harsh winter climate. The NCAT report concludes that “based on the results from this study, the use of WMA via the three technologies evaluated in this study is recommended to extend the paving season”. The full study can be found on the CAPA website.

Evotherm is the only warm mix asphalt currently approved by the Colorado DOT.