Viscosity-temperature characteristics of warm mix asphalt binder with Sasobit®

• Dynamic viscosity at 60 °C exponentially increases with additive dosage.
• Apparent viscosity above 110 °C exponentially decreases with temperature.
• Apparent viscosity above 110 °C linearly decreases with additive dosage.
• WMA binder with more additives is more temperature susceptive.

Two matrix asphalt binders are used to prepare warm mix asphalt (WMA) binders with different dosages of Sasobit® additive, and the general technical properties, the dynamic viscosities at 60 °C, the apparent viscosities above 110 °C are measured and analyzed. It is found that the apparent viscosity exponentially decreases with the increase in temperature and could be considered as independent on shear rate. The dynamic viscosity exponentially increases with the increase in additive dosage, but the apparent viscosity linearly decreases. The WMA binder with more additives is more temperature susceptive, and the different effects of the additive on the viscosity-temperature characteristics is mainly because of the temperature transition point of the additive around 100–110 °C. The additive improves both the high temperature property in serve stage and workability during construction. However, it worsens the low temperature property, which should be paid more attentions in practice.