MELO NETO, Osires de Medeiros.
Abstract:
The incorporation of more than 30% Reclaimed Asphalt Pavement (RAP) in asphalt mixtures
faces limitations due to the high stiffness of RAP, making the use of rejuvenating additives,
such as vegetable oils, necessary. In this context, babassu oil emerges as an alternative,
diversifying renewable sources and reducing reliance on a single input. This study evaluated
the feasibility of adding this oil to recycled mixtures through four stages: (i) physical,
chemical, and rheological characterization of virgin and recovered asphalt binders modified
with babassu oil contents ranging from 1% to 12%, including analysis of short- and long-term
aging effects; (ii) mechanical performance evaluation of mixtures containing 0%, 15%, 56%,
63%, and 70% RAP, using indirect tensile strength, resilient modulus, moisture-induced
damage, permanent deformation, fatigue, and abrasion tests; (iii) economic analysis
considering production costs and net present value (NPV), as well as the influence of
transportation distances; and (iv) environmental analysis based on circularity indices. The use
of babassu oil resulted in reduced stiffness of the recovered binders, mitigation of thermal
aging from 3% addition onward, and increased fatigue life under higher strain levels. The
recycled mixtures exhibited mechanical performance comparable to the control mixture in
most tests; however, the mixture containing 70% RAP and 7% oil stood out due to its superior
fatigue resistance. The composition with 70% RAP and 7% oil proved to be the most circular
and cost-effective, with production cost reductions of up to 72.98% per paved kilometer. The
integrated analysis of circularity, costs, and CO₂ emissions highlighted the potential of
babassu oil to enhance the efficiency and sustainability of recycled mixtures.
