Rheology and mix performance of rejuvenated high RAP field produced hot mix asphalt with a soybean derived rejuvenator. Issue 8 (3rd August 2021)

• Record Type: Journal Article
• Authors: Podolsky, Joseph H.; Saw, Barrie; Elkashef, Mohamed; Williams, R. Christopher; Cochran, Eric W.
• Is Part Of: Road materials and pavement design. Volume 22:Issue 8(2021)
• Page Start: 1894
• Page End: 1907
• Publication Date: 2021-08-03
• Subjects: Rejuvenator -- epoxidised methyl soyate -- Superpave -- moisture susceptibility -- rutting -- low temperature cracking -- field density; Road materials -- Periodicals; Highway engineering -- Periodicals; Pavements -- Design and construction -- Periodicals; 625.805
• DOI: 10.1080/14680629.2020.1719190
• Languages: English
• ISSNs: 1468-0629

Abstract

Abstract : A laboratory study was conducted to determine the optimum dosage of a bio-based rejuvenator, epoxidised methyl soyate (EMS), needed to obtain a mix design containing 30% unfractionated recycled asphalt pavement (RAP) using a neat asphalt binder with performance grade (PG) 58-28S, rated for standard traffic to meet performance criteria for a PG 58-28S. Based on running a comprehensive rheological characterisation using Superpave binder criteria, 3% EMS by weight of the neat binder was needed to obtain a PG 58-28S at proportions of (75.5% neat binder w/ 3% EMS, and 24.5% RAP extracted binder). The 3% EMS is equivalent to 0.126% by weight of the total mix. Through lab verification, the mix design with 0.126% EMS was shown to meet performance criteria for moisture susceptibility/rutting and low temperature cracking. Field produced mix with 0.126% EMS by weight of total mix was also shown to pass the performance criteria as well for the aforementioned properties. However, the field produced control mix with 20% RAP was not shown to pass criteria for low temperature at −18°C, and thus the field produced control mix became rated as a PG 64-22S. In addition, field density was checked for both the control mix and EMS RAP mix, where both sections had pay bonuses of 3.1% and 4%, respectively.