Improving the Performance of Asphalt Mixtures with Highly Acidic Aggregates in Central Vietnam Using Modifier Based on Styrene–Butadiene–Styrene and Rosin Resin

In Central Vietnam, the aggregate typically originates from highly acidic rocks containing a significant amount of silicon dioxide (SiO2), leading to poor adhesion quality with virgin asphalt binder. Hence, the asphalt mixture production usually needs to utilize adhesion promoters. Based on the chemical compositions of the sample aggregate (up to 72.3% SiO2), research has been conducted to introduce an adhesive agent called rubber modified compound (RMC-160), which is composed of styrene–butadiene–styrene (SBS) with petroleum hydrocarbon resin, treated clay and mineral oil. This article presents the research findings regarding the adhesion effectiveness of RMC-160–modified asphalt binder to high acid-based aggregate through laboratory and field tests, along with the mixture performance under both short-term oven aging (STOA) and long-term oven aging (LTOA). The test results exhibited remarkable effects, whereby the asphalt binder modified with RMC-160 additive significantly increased the adhesion level from Grade 2 to Grade 4, and the asphalt mixtures containing RMC-160 had lower rutting and higher cracking tolerance (CTIndex) under both the STOA and LTOA conditions.