Development of warm-mix asphalt additive and evaluation of performance

Several warm-mix asphalt (WMA) technologies have been developed and implemented worldwide. Because of the reduced production and compaction temperatures of WMA mixtures, WMA technology can reduce energy consumption, carbon dioxide emission, and asphalt oxidation as well as extend the paving season, increase hauling distance, and create a better working environment. A wax-based WMA additive called low-energy and low-carbon-dioxide asphalt pavement (LEADCAP), has been developed by the Korea Institute of Construction Technology and Kumho Petrochemical and is the first WMA additive developed in South Korea. This paper introduces the characteristics of this newly developed WMA additive and presents the performance evaluation of WMA with LEADCAP. To evaluate the performance of the WMA mixture with LEADCAP additive, the Superpave® mix design, moisture susceptibility test, and mechanical test were performed. Common hot-mix asphalt and a WMA mixture with Sasobit additive were also evaluated for comparison. Sasobit is also a wax-based additive and is well-known. Mechanical tests included the dynamic modulus test, the direct tension fatigue test, and the triaxial repeated loading permanent deformation test. From the limited data obtained in this study, it was concluded that LEADCAP could be effectively used in WMA mixtures and that the performance of WMA with LEADCAP could be expected to be comparable to that of hot-mix asphalt and WMA with Sasobit additive.