Effect of warm mix additives and dispersants on asphalt rheological, aging, and failure properties

Warm mix additives, asphaltene dispersants, and other chemical modifiers are regularly added to asphalt to improve workability during construction, to increase the useful temperature interval in service, or to impart other benefits such as enhanced resistance to chemical aging or moisture damage. There is a scarcity of information on how most of these additives affect durability. This report discusses how commercial and developmental additives affect low strain rheological and high strain failure characteristics. It was found that several modifiers significantly changed both rheological and failure properties. Hence, care is warranted in order to assure an overall benefit from such technologies.

► Warm mix additives can potentially increase pavement cracking.
► Paraffin inhibitors can potentially reduce thermal cracking.
► Effects are not easily predictable and hence best evaluated through improved performance testing.