The Southern Sydney Regional Organisation of Councils (SSROC) led Paving the Way (Recycled Rubber), an initiative to demonstrate the sustainability and durability benefits of repurposing rubber from end-of-life car and truck tyres to modify the polymers in bitumen. The initiative became a priority following China’s National Sword policy in 2017 that banned the import of co-mingled recycled materials and the Coalition of Australian Governments’ decision to ban exports of unprocessed recyclable materials in 2019.
A lack of viable end markets for recyclable materials increased upward price pressure for councils, creating a risk of losing valuable resources to landfill and jeopardising community confidence in recycling systems. Amidst these trends, SSROC sought solutions and the result was the SSROC’s Procure Recycled: Paving the Way initiative that leveraged market disruption, innovation and councils’ determination for sustainable pavements.
The initiative is an outstanding example of collaboration involving councils and industry. From 2021 to date, SSROC collaborated with Tyre Stewardship Australia that committed funding for independent evaluation, technical support and strategic advice to SSROC and Australian Flexible Pavements Association (AfPA) developed the technical and site monitoring framework to guide rubber-modified asphalt performance evaluation. It also demonstrated the immense strength of collaboration with councils’ teams across specialties including engineers, asset managers, procurement, sustainability and waste teams.
The project further entails investigating the production processes that convert tyres to usable material such as asphalt/bitumen production plants monitored the electricity-gas-water-oil consumptions to manufacture a standard unit (1 tonne) of recycled rubber-modified asphalt. These mixes are compared with their control mixes to inform environmental impacts.
Conference presentation will share the findings of the monitoring and evaluation work, the life cycle assessment that evaluated asphalt durability, oxidation, cracking and ageing of demonstration pavements and steps for technical specification process for using rubber-modified bitumen in pavements by council engineers.