Impact of soybean derived chemical additive on the morphology of asphaltenes extracted from virgin asphalt, polymer modified asphalt and recycled asphalt pavement extracted binder through small-angle X-ray scattering by solids and solids in solution

Abstract

Recent work has shown that epoxidized plant oil materials work well as rejuvenators in recycled asphalt pavement (RAP). At the end of the 2017 construction season, a field trial mix with 30% RAP (total recycled binder content of 30.3%) was produced and placed in Northwest Iowa on US-18, east of Sheldon, Iowa. The rejuvenator (SR) was used at a rate of 0.125% by total mix weight. The mix design for the control section used a PG 58-34H. Due to Iowa DOT specification (recycled binder content greater than 20%) a grade bump was needed for the binder in the SR trial section (PG 52-40H). With 0.125% SR by total mix weight the grade bump was achieved. To better understand the chemistry behind this rheological improvement two chemical characterization methods will be explored (SAXS/USAXS, and IM-MS) on the asphaltene portion of SARA fractions of several binders (PG 52-34, RAP, PG 52-34 w/polymer (PG 58-34H), PG 52-34 w/SR, PG 52-34 w/RAP, RAP w/SR, PG 58-34H + SR, PG 58-34H + RAP, PG 52-34 w/SR + RAP, and PG 58-34H + SR + RAP)