Asphalt materials have been a fundamental building material in highway construction for many years including its use as a binder in hot mix asphalt(HMA) and as an emulsion in various applications including base stabilization, cold mix recycling, chip sealing and tack coats. The substantial increase in crude petroleum, from which most asphalt binder is derived, has translated into substantial increases in asphalt binders and thus asphalt material prices over the past five years. The public is most keenly aware of the increases in crude petroleum as automobile fuel prices have increased as a result too. These increases in automobile fuels have also created opportunities for refineries to further examine the addition of value addedfacilities in the form of cooking facilities which would remove automobile fuel components from asphalts and therefore reducing the supply of asphalt binders for use in highway construction. The near and long term impactof reduced asphalt supply to the highway construction industry is substantial and translates into critical impacts on the nation's highways and economy as approximately 90 percent of the United States highways contain asphalt products. Substantial technological developments in the production and fractionation of bio oil, a product derived from fast pyrolysis of biomass, has the potential to be a beneficial asphalt additive/modifier/extender. Three biomass sources consisting of switch grass, corn stover and oak wood were pyrolized and fractionated in a pilot plant. The electrostatic precipitant (ESP) from the three biomass sources were blended with three different asphalt binders at 3, 6, and 9 percent by mass of the total binder and characterized. Characterization was done according to AASHTO M320 for grading a standard asphalt binder. Substantial benefits of blending theoak wood and switch grass ESP fractions with a polymer modified asphalt binder were identified.
Samenvatting