Pyrolysis Temperature Effects on Sugarcane Bagasse Bio-Oil for Reclaimed Asphalt Pavement Rejuvenation

Abstract

This study evaluates the performance of aged asphalt binders rejuvenated with bio-oils derived from sugarcane bagasse pyrolyzed at 200°C, 300°C, and 400°C. Each bio-oil was blended at 20% by weight into aged asphalt, and the rheological, thermal, and moisture susceptibility characteristics were assessed using Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), Performance Grade (PG) classification, GC-MS, and image-based boiling water tests. Temperature sweep tests revealed improved high-temperature performance across all rejuvenated binders. The F4-20 binder (400°C bio-oil) exhibited the highest rutting resistance, performing well up to 76°C, compared to 70°C for the base binder. All rejuvenated samples achieved a PG 76-22 classification, reflecting enhanced stiffness and thermal stability without compromising flexibility. At intermediate temperatures, P3-20 demonstrated the lowest fatigue factor, suggesting improved resistance to fatigue cracking. Low-temperature testing showed that P4-20 delivered the best performance at −12°C, with reduced stiffness and increased stress relaxation potential. However, performance declined for all binders at −18°C. GC-MS analysis confirmed that higher pyrolysis temperatures yield bio-oils rich in phenols and pyridine, which improve molecular compatibility and dispersion of asphaltenes. Image processing of boiling water stripping tests showed that rejuvenated binders exhibited reduced stripping percentages (<30%), indicating better moisture resistance compared to the base binder. These findings highlight the influence of pyrolysis temperature on the chemical structure and rejuvenating potential of bio-oils. The 400°C bio-oil (F4-20) emerged as the most effective formulation, offering a sustainable and high-performing solution for aged asphalt binder restoration.

Keywords: Bio-oil rejuvenator, Pyrolysis temperature, Sugarcane bagasse, rheological properties, Moisture susceptibility