Investigation of polymer-modified bitumen containing renewable components

Researchers are exploring the possibility of replacing bitumen with renewable biomass materials to reduce the dependency on crude oil. However, to date, only marginal research has been devoted to using renewable materials to modify or partially replace polymer-modified bitumen, which is currently widely used for pavements subjected to significant heavy traffic. In this context, this study compared an SBS polymer-modified bitumen ('PMB') with two bio-binders consisting of PMB and components from renewable sources, including dry lignin. The binders were investigated in terms of storage stability, linear viscoelastic behaviour, fatigue performance, permanent deformation resistance, adhesion with typical aggregates and ageing susceptibility by means of physical, mechanical and chemical tests. The results show that all performance and durability properties of the studied bio-binders can be considered comparable to those of the reference PMB. These outcomes encourage the study of asphalt mixtures produced with the same bio-binders for possible application in heavy-traffic pavements.