Rheological performance of soybean in asphalt binder modification

This study investigated the incorporation of soybean oil, first in the ranking of Brazil production, in a partial substitution to two types of asphalt binder (pure and with Styrene–Butadiene–Styrene – SBS) in order to produce warm-mix asphalt (WMA). The oil was incorporated into two conditions: new and waste, and the mix was obtained with 1%, 2% and 3% of soybean oil. The samples were analysed using the tests of penetration index, softening point, rotational viscosity, performance grade (PG), and multiple stress creep and recovery (MSCR). The results show that the addition of 1% content of new and waste soybean oil improved physical and rheological characteristics of asphalt binders. The decrease in mixing and compaction temperature was obtained in 2.7°C average for 1% of waste oil with pure asphalt binder and 3.4°C average for a 1% of new oil with asphalt binder with SBS, considering only the criterion of the viscosity curve.