Gilsonite Modified Asphalt for Use in Pavement Construction

Properties such as durability and moisture resistance of asphalt concrete significantly improve pavement service life. When siliceous aggregate is used, then preventing moisture damage and stripping become distinctly required. Typically, stripping could be prevented by either using antistripping agents or by modifying the binders. The anti-stripping agent achieve its purpose by changing the aggregates' affinity for water through changing the zeta potential (promote bitumen adsorption due to negative surface charge). On the other hand, modifications of binders promote interface bonding between aggregate particles and bitumen. However, the process of applying anti-stripping agents or adhesion promoters is typically costly and, in some cases, may negatively impact other performance characteristics of pavement. Accordingly, this paper examines the merit of applying natural bitumen (gilsonite) instead of typically used anti-stripping chemicals in order to both promote resistance to moisture damage and reduce construction cost in asphalt. In addition to being quite low-cost, Gilsonite has a chemical composition nearly similar to that of petroleum based asphalt which makes it very compatible with asphalt binder.