Feasibility Assessment of Warm Mix Asphalt in Arkansas

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