Avaliação da amida de óleo de soja residual como aditivo em misturas asfálticas mornas: impactos na adesividade e nas propriedades reológicas do ligante asfáltico

Abstract

The increasing demand for sustainable solutions in pavement engineering has driven research into renewable additives to enhance the properties of asphalt binders. This study evaluated the use of amides derived from waste soybean oil (AOF) as additives in asphalt binders, analyzing their effects on reducing mixing and compaction temperatures (MCT), adhesion, and rheological properties. The amides were synthesized through the reaction between methyl esters and ethanolamine and incorporated into the binder at concentrations of 1%, 3%, and 5% by mass. The results indicate that the addition of 3% and 5% AOF reduced binder viscosity by up to 26.2% and 35.2% at 135 °C, respectively, facilitating application at lower temperatures. The average mixing temperature was reduced by 7 °C with 3% AOF and by 9.5 °C with 5% AOF compared to the pure binder, while the compaction temperature decreased by 7 °C and 9.5 °C, respectively. These reductions reflect improved energy efficiency in the paving process. Additionally, AOF modification reduced binder stiffness, as evidenced by the decrease in the complex modulus |G*|, while the increase in the phase angle (δ) indicated a more viscous behavior. Adhesion also improved significantly, with the binder-covered area on aggregates increasing from 35.4% (pure binder) to 89.9% (LA + 3% AOF) and 93.7% (LA + 5% AOF). These findings confirm that amides derived from waste soybean oil are a viable alternative for modifying asphalt binders, promoting lower mixing and compaction temperatures, improving adhesion, and enhancing the sustainability of the paving process.