Supported by the Australian Research Council, Austroads and 10 Victorian councils, RMIT University will spearhead a project that will use recycled plastics to create new roads.

These recycled plastics-asphalt roads will incorporate soft plastic from consumer and industrial waste and will be stationed at 10 different locations across Victoria, as it seeks to demonstrate a viable circular-economy solution to the nation.

Over the coming months, sections of recycled road up to 900 metres long will be paved in the City of Melbourne as well as in nine suburban and regional councils.

2.6 million tonnes of plastic waste is generated in Australia each year and landfill space is expected to reach capacity by 2025.

This project will help to address this problem as the 10 project sites will use an estimated total of 21,000 kg of recycled plastic.

RMIT University School of Engineering Associate and Project Leader 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.

“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,” said Giustozzi.

Funded by Austroads and published in Science of the Total Environment, the project team’s latest study found that the recycled plastic and asphalt mixtures resulted in 150 per cent less cracking and 85 per cent less deformation under pressure testing than normal asphalt.

“The performance of roads can actually be improved with the additions of recycled material, such as plastic and rubber, to be more durable against traffic and resistant against ageing.

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

“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,” said Giustozzi.

Other RMIT University-conducted laboratory studies also show that these mixtures are mechanically, chemically and environmentally sound.

Austroads Chief Executive Geoff Allan said the project builds upon the work completed in 2022 which confirmed that recycled plastics can be successfully incorporated in road infrastructure without any detrimental effects on the environment, general health and safety and the future of recyclability.

“A major contribution of this project will be to develop evidence-based guidance that will provide certainty to road managers about the use of recycled plastics in road surfacing applications and thus lay the foundations for this solution to be embraced nationally,” said Allan.

The project will be coordinated under the ARC Industrial Transformation Research Hub for Transformation of Reclaimed Waste Resources to Engineered Materials and Solutions for a Circular Economy (TREMS).

Local government areas involved include City of Melbourne, Banyule, Bayside, Moonee Valley, Hobsons Bay, Baw Baw, Latrobe, Casey, Mornington Peninsula and Wyndham.