Feasibility Assessment of Warm Mix Asphalt in Arkansas

<p>The future of Warm Mix Asphalt (WMA) technologies is promising in the U.S. However, the Arkansas Department of<br> Transportation (ARDOT) does not have any specific guidelines to implement them in the field. This research aims to<br> provide necessary baseline data for WMA as a proof of concept. In this study, three ARDOT approved Performance<br> Grade (PG) binders namely PG 64-22, PG 70-22, and PG 76-22 were investigated. Each of these binders was obtained<br> from two different sources. They were modified by varying doses of four selected additives: Sasobit&reg;, Advera&reg;,<br> Evotherm&reg;, and Rediset&reg;. Additionally, four different types of aggregates (sandstone, limestone, gravel, and dolomite)<br> from different quarries in Arkansas were evaluated for their compatibility with modified binders. Empirical test<br> (Penetration test), Superpave Performance tests such as Rotational Viscometer, Rolling Thin-Film Oven (RTFO),<br> Pressure-Aging Vessel (PAV), Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer), PG Plus tests such as<br> Multiple Stress Creep Recovery and Frequency Sweep, chemical analyses (SARA analysis, FTIR, pH), science-based<br> test (Surface Free Energy), and Texas Boiling Test on loose mixture samples were conducted at different aging<br> conditions. Based on the RV test results, reduced mixing and compaction temperatures have been observed for Sasobit&reg;,<br> Evotherm&reg;, and Rediset&reg; modified samples. The DSR test results suggest that both Sasobit&reg; and Advera&reg; can reduce rut<br> potential. On the other hand, BBR test results indicate that both Evotherm&reg; and Rediset&reg; have the capabilities of<br> improved resistances against fatigue and low-temperature thermal cracking. Binder samples modified by these have also<br> demonstrated minimal stripping in SFE and Texas Boiling Test. Advera&reg; has modified the chemical compositions of the<br> neat binders, which was also observed in the SARA analysis. The findings of this study will help the agency to select the<br> most appropriate WMA additive along with its application rate.</p>