DEVELOPMENT AND EVALUATION OF A WARM-MIX ASPHALT ADDITIVE THROUGH ASPHALT MIXTURE PERFORMANCE TESTS AND ANALYSES

摘要

This paper employs comprehensive performance-based evaluations of asphalt mixtures todevelop the organic wax-based, warm-mix asphalt (WMA) low energy and low carbondioxide asphalt pavement (LEADCAP) additive through advanced laboratory tests andanalyses. The performance evaluation adapted in this study contains fatigue cracking,rutting, and moisture susceptibility. The fatigue performance with and without moistureconditioning is investigated using direct tension cyclic tests coupled with simplifiedviscoelastic continuum damage (S-VECD) models and layered structural analysis.Moreover, the stripped areas on the specimen surfaces that are fractured during the directtension cyclic testing are quantified. Triaxial repeated load permanent deformation andasphalt pavement analyzer (APA) tests are conducted to assess the rutting potential.The fatigue test results exhibit that the WMA-B mixture has a comparable performance tothe HMA mixture, but the WMA-A mixture’s performance is worse than the HMA andWMA-B mixtures’ performances. The rutting test results show that the WMA-A and WMABmixtures have greater rutting resistances than the HMA mixture. However, the results ofthe fatigue life ratio and stripping percentage tests indicate that the WMA-B mixture ismore susceptible to moisture damage than the HMA mixture. Finally, the polyethyleneWMA-D additive combined with a crystal controller and an adhesion promoter wasdeveloped by improving the moisture susceptibility while maintaining the fatigue andrutting performance of the WMA-B additive.