The implementation of warm mix asphalt (WMA) is becoming more widespread with a growing number of contractors utilizing WMA technologies to take advantage of reduced mixing and compaction temperatures, reduced fuel consumption and improved compactability. WMA technology has demonstrated to have beneficial economic value as well as environmental value in other parts of the United States and Europe. The identified economic value is due to the reduction of hot mix asphalt (HMA) plant temperatures by 50-100°F, saving fuel and allowing for improved field compaction (reduction in roller coverage) and/or longer haul distances. The environmental benefits of WMA additives include reduced HMA plant emissions because of the reduced plant production temperatures as well as reduced worker exposure to fumes during the production/construction process.

This research was completed in two phases. Phase I showed differences between control HMA mixes and WMA mixtures in moisture conditioning and dynamic modulus performance. Phase II of this study further evaluated the performance of plant-produced WMA mixtures. This is done by conducting more mixture tests at a broader range of temperatures, adding the Hamburg wheel tracking test, adding additional pavements to the study, performing pavement condition surveys and comparing WMA and HMA pavement condition data with the mechanistic-empirical pavement design guide's forecast for pavement damage over the next 20 year