4.1 Biomass-sourced Bitumen Pavements
Over time, it is expected that oil prices will continue to fluctuate, and as the availability of oil becomes more limited, alternative materials to bitumen will in turn be not only more attractive but also necessary. Such options include vegetable-oil-based (VO-based) bitumen mixes and molasses-based bitumen products. Bitumen from renewable sources has the potential to reduce the impact of increasing oil prices, in the longer term, on asset management by providing a material that is not directly dependent on oil for its production, and therefore not as directly sensitive to rising oil prices. There is, however, a need for further research into the following:
- the long-term performance and lifetime of biomass-sourced bitumen pavements and how the performance of these alternative sources of bitumen in pavements is evaluated
- estimation of the investment needed for new equipment and required re-training
- estimation of the cost of using biomass-sourced bitumen pavements in the field
- estimation of the exact scale of available raw material, i.e. to what extent does the quantity of suitable plant waste from the agriculture industry allow biomass-sourced bitumen to replace fossil‑oil‑based bitumen? (Austroads 2010a).
In addition to this work, Austroads undertook two further projects examining the future availability and assessment of alternative surfacing binders and investigating the properties of alternative surfacing binders and bitumen extending binders (Austroads 2012a, 2012b and 2013).