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Advanced characterization of bio-rejuvenated asphalt systems using agricultural waste pyrolytic oils: Integrated assessment of chemical composition, rheological, and aging performance
Author(s)
Date Issued
April 4, 2026
Type
Article
Abstract
Reclaimed asphalt pavement (RAP) requires rejuvenation to restore binder flexibility lost due to oxidative aging. This study evaluated sugarcane bagasse oil (SBO) and rice straw oil (RSO) as bio-rejuvenators using an integrated chemical (GC–MS, FTIR), rheological (master curves), and mechanical (LAS fatigue) framework. GC–MS confirmed distinct feedstock chemistries—SBO enriched with methoxy-phenolics and aromatics, and RSO dominated by catechol, nitrogenous species, and oxygenated sugars—suggesting different rejuvenation pathways. FTIR results showed reduced sulfoxide index (SI) in fresh rejuvenated binders, indicating dilution of S O groups; however, changes in carbonyl index (CI) largely reflected the inherent bio-oil composition rather than true oxidative reversal. Several FTIR indicators therefore contrasted with rheological and fatigue behavior, demonstrating that chemical indices alone cannot fully describe rejuvenation or aging progression. Rheological master curves and LAS testing provided the decisive evidence of performance. Fresh rejuvenated binders exhibited substantial stiffness reduction and improved relaxation, with optimum dosages of ≈ 15% SBO and 10–15% RSO achieving 2–5 × higher fatigue life than aged binder at moderate to high strains. Following secondary aging (P-series), rejuvenation benefits were substantially diminished, with fatigue performance returning to aged-binder levels at most strain ranges. Only minimal-dosage formulations (5% SBO) demonstrated statistically significant protection against unprotected secondary aging (2AB, p < 0.05), while moderate-to-high dosages (10–20%) showed equivalent or inferior performance. FTIR indices revealed reduced sulfoxide formation in all P-series binders compared to 2AB, suggesting partial oxidation mitigation through alternative carbonyl-forming pathways, though this chemical protection did not translate to sustained mechanical performance. Thus, while hypotheses on feedstock-dependent chemistry and dose–response behavior were validated, sustained antioxidant protection from phenolics was only partially supported. In conclusion, chemical findings indicate potential rejuvenation mechanisms, but performance tests ultimately govern evaluation, and long-term durability will require hybrid formulations incorporating stabilizing additives.
Citation
Construction and Building Materials, 518, 2026