Due to the rising price of crude oil, flexible pavement costs have increased significantly. This price pressure has resulted in the increased use of reclaimed asphalt pavement (RAP) and/or reclaimed asphalt roofing shingles (RAS) because of the binder (asphalt cement) they contain. This has increased demand for recycling (rejuvenating) agents which return the RAP/RAS binders to their original state by 1) restoring maltenes (petroleum oils and resins) that have been depleted due to age-hardening/oxidation, and 2) reducing their viscosity. The project concept was to design a flexible pavement mixture (FPM) produced with little-to-no virgin petroleumbased binder which implied the use of high percentages of RAP and/or RAS, and a bio-based virgin binder. The potential impacts of a renewable (bio-based), domestic source of FPM binder on highway construction could be lower costs and, perhaps more importantly, a decreased dependence on foreign oil.
Available at: http://works.bepress.com/david_richardson/53/