Evaluation of the Performance ofWarm Mix Asphalt inWashington State

Warm mix asphalt (WMA) is a relatively new and emerging technology for the asphalt industry. It offers potential construction and environmental advantages over traditional hot mix asphalt (HMA). However, WMA must perform at least as well as HMA before it can be used to replace HMA. This study evaluates the performance of HMA and WMA mixes obtained from various field sites in the state of Washington. Different WMA technologies are examined in four separate projects; these technologies include Sasobit® and three water foaming technologies, Gencor® Green Machine Ultrafoam GX®, Aquablack™ and water injection. Performance tests are conducted on the cores and extracted binders to evaluate the resistance of HMA and WMA samples to fatigue and thermal cracking, rutting and moisture susceptibility. Additionally, the early-age field performance of WMA and HMA control pavements is compared.