The road to a circular economy – research to test best recycled tyre mix

Tyre Stewardship Australia and RMIT University are partnering on a ground-breaking research project evaluating the performance of crumb rubber in asphalt made from old car tyres.

The project, co-funded by TSA, RMIT and the Victorian Department of Transport (DoT), will evaluate to what extent and in what proportion – when mixed with truck tyres, for instance – passenger car tyres can be recycled in road asphalt pavements.

Dr Filippo Giustozzi from RMIT University, the leading academic institution in Australia for asphalt and bitumen research and development, said the research project would look to address barriers to the increased consumption of recycled Australian passenger tyres in the growing road sector for crumb rubber.

“Currently, most crumb rubber asphalt and sealing use recycled tyres from trucks almost exclusively. That’s because truck tyres have a higher content of natural rubber, thus better chemical compatibility with bitumen. Most recycling infrastructure in Australia is currently set up to process truck tyres into crumb and granule because the market for passenger tyres is so small. Through this research project, we want to objectively ascertain whether there are any performance differences between passenger and truck tyres in asphalt road applications,” he said.

“We will use passenger car tyres – or a combination of truck and passenger tyres – to produce crumb rubber mixes with 5 to 20 per cent rubber.”

Tyre Stewardship CEO Linda Goodman said Australia generates the equivalent of 56 million used car tyres every year. She said around 30 per cent of those end up in landfill or are stockpiled. 85 per cent of end-of-life passenger tyres are recovered and exported.

“This evidence-based research will allow the road industry to respond to the increasing push of the Australian Government for recycling more while ‘exporting’ less.”

“Through partnerships like this research project with RMIT and DoT, Tyre Stewardship Australia is constantly looking to find innovative and sustainable ways to push towards a circular economy that can eliminate waste and support the continual use of resources, including the best recycled blends for better roads and a better environment.”

The research project is believed to be the first of its kind testing crumb rubber from passenger car tyres in bitumen and asphalt in Australia. The study, which begins this week, will run bitumen lab testing until July 2021, with asphalt testing completed a year later.