Ligninn i bindemedel för hållbara asfaltbeläggningar. Reologiska undersökningar

Sammanfattning: Bio-based binders have recently been introduced to reduce the dependence on fossil raw materials, which bitumen is produced of. Measurements with dynamic shear rheometer (DSR) and rotational viscometer (RVB) were performed on mixtures with bitumen and two different types of bio-based binders, namely Lignin 1 and Lignin 2. Parameters like softness point, viscosity and parameters used to evaluate rutting resistance, fatigue resistance and low temperature properties were obtained from the measurements. The results showed that rutting resistance increased as the content of lignin increased. Also, viscosity and softness point increased as content of lignin were increased. However, fatigue resistance, low temperature resistance and ductility were reduced as the content of lignin were increased. Finally, the obtained results from the elastic and viscous properties were compared with results reported from earlier studies using granite filler and Sasobit wax as additives. In this regard, the granite filler showed better agreement with Lignin 2. Results obtained from the RVB measurements showed that changes in viscosity for the lignin mixtures were more similar to the mixtures containing granite filler mixtures rather than mixtures containing Sasobit wax. This indicates that Lignin 1 and Lignin2 have no melting point within the tested temperatures due to Sasobit is an additive with a melting point.