Six South Australian councils have agreed to take part in a ground-breaking trial using crumb rubber derived from end of life truck tyres.

The agreement is between Tyre Stewardship Australia (TSA), Topcoat Asphalt Contractors Pty. Ltd. (Topcoat Asphalt) and the cities of Mitcham, Port Adelaide Enfield, Campbelltown, West Torrens, Onkaparinga and Salisbury.

The SA Department of Planning, Transport and Infrastructure (DPTI) is providing technical advice and is interested in the trial results. TSA has provided funding for the project which will see a special gap graded asphalt modified with crumb rubber replacing regular asphalt on a number of roads.

Tyre Stewardship Australia was formed five years ago to implement the national Tyre Product Stewardship Scheme which promotes the development of viable markets for end-of-life tyres.

It’s a voluntary scheme, made up of representatives from across the tyre supply chain including tyre retailers, manufacturers, auto-brands, recyclers and collectors.

“This trial is the largest one of its type conducted so far in Australia”, said TSA CEO, Lina Goodman.

“These councils are playing a vital role in finding modern and environmentally sound solutions to a problematic waste problem,” Ms Goodman said.

“South Australian Councils are leading the way by embracing this landmark opportunity in the development of the circular economy in Australia.

“Each year, the equivalent of 29 million passenger tyres are upcycled, recycled or processed locally for productive uses such as roads, playgrounds, polymers and tyre derived fuels. But, over 27 million passenger tyres in Australia are not being recycled.”

These often end up in landfill, stockpiles or are exported overseas. The trial will use the equivalent of around 3400 passenger vehicle tyres or more than 20,000 kilograms of crumb rubber. Each of the six sites will use what equates to 566 passenger tyres. Topcoat Asphalt will mix the crumb rubber into a special high-grade mix with a high rubber ratio.

The mix is based on specifications used in California where crumb rubber is commonly used in roads.

Each trial site will consist of two adjacent road sections. One 200-metre section will contain the high-grade mix and the other will be normal asphalt. The roads will be tested for resistance to rutting, susceptibility to cracking and moisture damage over a minimum of two years. A similar trial was conducted earlier this year on a small section of road in the City of Mitcham, which is so far showing positive results.

However, this larger trial will use a higher proportion of crumb rubber.

“I believe more councils and other levels of government should be using this technology in their roads,” said City of Mitcham’s Principal Engineer, Russell King.

“We have shown through our trial that it improves the performance of roads due to less cracking and it increases the life span.”

Topcoat Asphalt, Technical Manager, Rod McArthur said, “We already know crumb rubber from old tyres works well and even out-performs regular asphalt in other countries. This trial is about proving that the product works just as well in South Australia, using the tried and tested Californian technology, without having to reinvent the wheel.”

It is hoped the trial will encourage more councils and governments to use crumb rubber in the road network.

TSA has committed $5 million to a range of Australian projects using waste tyres, including horse racing tracks, car parks, sports grounds, playgrounds and even blast proof construction materials.

“This is a no brainer,” said Goodman.

“It’s a win-win for the rate payer and the environment by improving the asphalt performance and removing old tyres destined for landfill. It’s time we saw old tyres as a valuable product that can be used to make roads last longer all around Australia.

“The recent COAG announcement banning the export of old tyres is another reason governments should embrace this technology.”