The Effect of Sasobit Addition on Reducing Mixing and Compaction Temperatures of Asphalt

Abstract

This research investigates the effect of adding Sasobit, an organic wax-based warm mix asphalt (WMA) additive, on reducing the mixing and compaction temperatures of asphalt binder without compromising the mechanical performance of the asphalt mixture. The primary problem addressed is the high energy consumption and harmful emissions associated with conventional hot mix asphalt (HMA) production, which requires temperatures between 150–180°C. Sasobit is known to lower the viscosity of bitumen at high temperatures, thereby improving workability at lower temperatures. The main objectives are to quantify the reduction in mixing and compaction temperatures, evaluate the rheological properties of modified bitumen, and assess the mechanical characteristics of the resulting asphalt mixture. The significance lies in promoting sustainable road construction through reduced fuel use, lower greenhouse gas emissions, and improved worker safety. The methodology involved preparing asphalt binder samples with Sasobit dosages of 1%, 2%, and 3% by weight of bitumen. Rotational viscometer tests were conducted to determine viscosity-temperature curves. Marshall mix design, indirect tensile strength, and moisture susceptibility tests were performed on asphalt concrete specimens. Results showed that adding 2% Sasobit reduced mixing and compaction temperatures by approximately 20–30°C compared to control HMA. Higher Sasobit content further reduced temperatures but slightly affected low-temperature flexibility. The study concludes that Sasobit is highly effective in producing WMA with adequate mechanical properties and environmental benefits. Recommendations include using 2% Sasobit for optimal performance and conducting field validation studies.