With a staggering 51 million used tyres discarded annually in Australia, engineers have found a more sustainable, effective way of recycling them and keeping them out of landfill.
At present, only 5% of used tyres are recycled in Australia but engineers from the University of Melbourne are working with Tyre Stewardship Australia and Merlin Site Services to use them for permeable pavements.
Dr Mahdi Miri Disfani, who specialises in infrastructure at the university, said the current number of recycling solutions for tyres is limited to playgrounds, landscaping or asphalt layers but could be expanded to pavements and roads.
The research team is currently trialling four different pavement recipes for footpaths, bike paths, car parks; and areas of low-volume traffic.
“It’s a fine balance between recycled tyre particles, rigid rock aggregates and the binder,” Dr Disfani said.
“Using all of the qualities that make our humble tyre – sturdiness, elasticity and reliability - we want to create a surface that will deform when no load is present, and squeeze tyre particles tight to bring rigid particles together quickly to support heavy loads such as trucks, cars, buses and bikes.”
A range of performance requirements are being continuously tested and monitored which include skid resistance, pavement movement, water infiltration and run-off, and resilience under applied service loads.
But stormwater management is also a common issue in most major cities so Dr Disfani sees this project as a viable solution to saving water and reducing pollution to waterways.
“Currently, when Melbourne is hit with a major downfall of rain, within minutes we see busy inner-city roads flooded,” he said.
“The open structure of the permeable pavement allows enough water to infiltrate and flow through to the many collection systems and nearby gardens around the city.
Dr Disfani revealed that by modifying the design and adding extra layers beneath the surface, the team could guarantee no surface run-off, even under the heaviest Melbourne rainfall.
Image: With promising early results, Liam OKeefe from Tyre Stewardship Australia is hopeful this research will deliver real world impact and a “dramatic effect on sustainability”. Source: Flickr/Paul Sableman via Uni of Melb.