Bio-Degradable Wax to Modify Asphalt Binder for Warm Mix Asphalt

In order to reduce production and compaction temperatures, as well as to increase the resistance to permanent deformation, synthetically refined waxes are commonly used as additives in asphalt pavements. This study focuses on the capability of replacing synthetically refined wax with bio-degradable wax. Ten different bio-waxes (called Biomer) with varying melting ranges and composition, as well as three conventional waxes (Sasobit((R)), Licomont((R)), and Asphaltan) are mixed with a virgin bitumen of standard type 50/70. Different conventional and rheological properties are determined for these viscosity-modified binders to evaluate the effect of the waxes. Two promising Biomer waxes (BIT111 and BIT140) were identified, which show almost identical results compared to Sasobit((R)) and Licomont((R)), respectively. The results indicate that replacement of synthetic wax by bio-degradable wax is technically feasible. Additionally, the potential of asphalt pavements to form a source of microplastic is evaluated in this study. It is found that bitumen and wax cannot be considered as a source of microplastic.