Impact of Sasobit/Bio-oil Combination on The Performance of Asphalt Binders

• Sasobit creates a synergistic cross-link with DSO, enhancing performance at 0.5% DSO, but weakening at higher levels. • The best results are 2% Sasobit and 0.5% DSO, showing improved G* values and lower phase angles. • Sasobit and DSO significantly lower mixing and compaction temperatures; 2% Sasobit + 0.5% DSO achieves the highest PG temperature of 76°C. • Increased DSO content enhances fatigue resistance, reflected in better LAS testing results at intermediate temperatures. • Additional studies on the chemical and microstructural interactions of WMA additives and bio-oils are recommended to optimize performance. Asphalt pavements are the backbone of the highways. Research has been conducted to enhance the performance of asphalt binders and mixes. Part of the enhancement is utilizing waste bio-oil and warm mix additives. Sasobit, an organic wax, is used as the WMA additive, and date seed oil (DSO) was added to assess the high- and low-temperature performance. Mechanical tests were conducted to investigate the physical properties, while rheological tests were done to assess the viscoelastic performance. Two percent Sasobit was added to the asphalt binder and mixed with 0.5, 1.5, 2.5, 3.5, 4.5, and 5.5% DSO. The results show an increased high-temperature performance at 2% Sasobit + 0.5% DSO, with a reduced performance with increased DSO content. Contrary to the performance, the viscosity decreases with the increase in DSO. An increase in DSO is favored at low temperatures to decrease thermal cracking.