Time Travel Through Asphalt Bio-Binder Innovations

An increasing number of researchers and industrial partners have turned towards biomasses as promising materials for bitumen substitution. This exploration has led so far to a number of patented bio-binders from different stream sources, as well as test tracks and small-scale applications. Considering the relatively short period of research behind these materials, the research community has not yet optimised the design and production of a bio-binder that can completely or partially substitute bitumen in a successful and efficient way. This short review provides an overview of the approach and results of the most significant bio-binder patents and applications thus far. The overview covers a range of materials like natural resin, microalgae and lignin, and innovations like coloured pavements and test tracks with combined bio-materials. It highlights that some materials resulted in good cracking and rutting resistance, while others reported viscoelastic properties similar to bitumen. Finally, this short review stresses the need for a deeper understanding of the fundamental principles and the interaction mechanisms of the materials, which are essential for future research and applications of bio-sourced materials in the asphalt field.