Assessment of rheological properties of asphalt binder modified with babassu oil

Abstract

Reducing dependence on specific types of vegetable oils for Reclaimed Asphalt Pavement (RAP) rejuvenation is critical. Babassu oil, extracted from palm trees, emerges as a promising candidate. This study evaluates the addition of babassu oil to asphalt binder (penetration grade 50/70) in proportions ranging from 1 % to 12 %. Both direct addition of the oil and incorporation as part of a modified binder in long-term aged binder were tested. A total of 41 samples underwent physical and rheological testing, complemented by aging protocols. The findings indicate that babassu oil significantly decreases binder stiffness, as evidenced by reduced viscosity and performance grade. Samples containing 7–12 % oil enabled the production of warm mix asphalt at temperatures between 141°C and 150°C. The addition of 3 % or more oil mitigated the effects of thermal aging. The oil-modified binder demonstrated superior performance compared to direct oil addition in terms of reducing the stiffness of aged binder. Higher oil contents (greater than 4 %) enhanced the interaction, potentially allowing for an increase in RAP content. The integration of babassu oil into asphalt not only improves sustainability but also enhances economic efficiency, thereby supporting the principles of a circular economy.

Keywords

• Aging
• Costs
• Rejuvenating agent
• Rheology
• Stiffness
• Vegetable oil