Production, Placement, and Performance Evaluation of Warm Mix Asphalt in Texas

This paper documents the first warm mix asphalt field trial placed by the Texas Department of Transportation in 2006 using the emulsion based technology (Evotherm) developed by MeadWestvaco. The production, laydown, and compaction characteristics of warm mix were compared with a conventional hot mix asphalt control using a standard mixture design. Field-mixed, lab compacted samples were evaluated for production density, moisture susceptibility and cracking resistance. Field cores were obtained after one month and one year of service and evaluated using Hamburg Wheel-Tracking Tests and the TTI Overlay test. Cores were also evaluated using X-Ray computed tomography to determine the distribution of air voids versus depth in the compacted sample. Field performance of the warm mix is comparable to the hot mix control section after two years of service.