Investigation of Isosorbide Distillation Bottoms as a Bio-Based Warm-Mix Additive

Abstract

Biorefineries are increasing in number and size and include products based on food, energy, and chemicals. Depending on size and targeted products, biorefineries produce distillation bottoms with surfactant characteristics in sufficient quantities that can be used as a warm-mix asphalt (WMA) technology. Isosorbide distillation bottoms (IDB), having amphiphilic properties much like a classical ionic surfactant, are derived as coproducts of bio-based chemical production and show potential for reducing mixing and compaction temperatures as well as having low-temperature performance grade (PG) benefits. The objective of this paper is to evaluate the performance and potential of IDB as an asphalt additive through asphalt binder testing and mixture testing. Binder gradations were conducted for multiple binders at several dosage rates to verify compatibility with various petroleum crude sources and determine the optimum dosage level. Testing indicates promising results and shows an optimal dosage rate at approximately 0.5% by weight of binder. Mixture testing was performed to evaluate the impact of IDB on mix compactability and moisture susceptibility. Laboratory mixture and binder testing show favorable results for further implementation of IDB as an asphalt additive.