The rutting and stripping resistance of warm and hot mix asphalt using bio-additives

Isosorbide distillation bottoms (IDB) are a co-product from the conversion of sorbitol to isosorbide and have been shown to improve low temperature binder performance when tested in the bending beam rheometer. With the successful inclusion of IDB into asphalt, other bio-chemical streams with similar properties to IDB are of interest. The incorporation of bio-additives that create softening of the binder require an evaluation of rutting resistance. To use bio-based chemical additives as a warm mix asphalt modifier, moisture susceptibility must also be examined. The objective of this paper is to evaluate how IDB and several new bio-derived material additives influence the rutting and stripping resistance in WMA binders and mixtures. Rutting resistance of short term age binder is evaluated using the multiple stress creep recovery (MSCR) test and hot mix asphalt (HMA) and WMA evaluation will employ the Hamburg Wheel-Tracking Device (HWTD) test. Reduced mixing and compaction temperatures were achieved with all bio-additives. MSCR and HWTD results using the bio-additives with non-polymer modified binder show no improvements but when with a polymer modified (PM) binder, all additives show statistical improvements in resistance to rutting and stripping compared to a PM control.