New technology is being tested in roads mixed with recycled plastics across Victoria.

An RMIT University-led project - supported by the Australian Research Council, Austroads and 10 Victorian councils - will incorporate recycled plastic from consumer and industrial waste, including notoriously stubborn soft plastics, into asphalt as a performance enhancer.  

With Australians generating 2.6 million tonnes of plastic waste each year and landfill space expected to reach capacity by 2025, this project is helping to address an urgent challenge. 

Project lead, RMIT Associate Professor Filippo Giustozzi, said the team will also produce best-practice guidelines on the use of recycled plastics in asphalt roads.  

“These guidelines will enable local governments, which control 80 per cent of the nation’s roads, to begin widescale adoption of this innovative recycling solution,” said Giustozzi from RMIT’s School of Engineering. 

The City of Melbourne and nine suburban and regional councils will lead the way, each having sections of recycled road up to 900 metres long paved over coming months. 

The 10 project sites will use an estimated 21,000 kg of recycled plastic, but the potential scale of this solution is considerable given the several hundred thousand kilometres of roads across Australia, Giustozzi said. 

“If Australia’s 537 local governments each used a small amount of recycled plastic in the many roads they resurface each year, then nationally we’ll have created a large end-market for recycled plastic.” 

Research has shown that the performance of roads can actually be improved with the addition of recycled material, such as plastic and rubber, to be more durable against traffic and resistant against ageing.

The team’s recent study found the recycled plastic asphalt mixtures had 150 per cent less cracking and 85 per cent less deformation under pressure testing than conventional asphalt. 

“These studies tell us that adding specific types of plastic in the right way can generate greater rutting and fatigue resistance,” Dr Giustozzi said.  

“In some instances, the performance of the mix was similar to some of the more expensive polymers used in roads and substantially higher than conventional asphalt mixes.” 

More details are accessible here.