New research by the University of the Sunshine Coast could enable wider use of plastic recycling technology to reduce carbon emissions in road construction across the globe.

The results are exciting for Scottish student Finn Hall, who didn’t let international border closures stop him completing a Master of Science with USC over the past two years.

Finn used a local Scottish county for the final implementation study that demonstrated the effectiveness of using local kerbside rubbish instead of industrial waste products as materials for more sustainable road engineering.

The study showed that readily available household and retail plastic waste could be an effective binder modifier in asphalt production, not only improving the engineering properties of local road surfaces, but also resulting in significant carbon emission savings.

“This also creates a circular economy, with the plastic pollution recycled into the civil engineering industry,” said Finn, who was supervised remotely by USC Engineering academics Dr Greg White and Dr Adrian McCallum.

Dr White said previous research had associated waste plastics with improvements in asphalt strength, as well as environmental benefits, but there were knowledge gaps preventing the widespread and universal application of ‘plastic roads’.

“This research helps address those gaps and overcome challenges by investigating some of the practical concerns raised by road owners and practising engineers,” he said.

“These include the potential for leachate (waste liquid) and fumes, the workability during construction, the environmental durability in the field, and the different methods of incorporating waste plastic into bitumen and asphalt.

Finn, who also has a Civil Engineering degree with Honours from The University of Strathclyde (Scotland), said he developed a passion for sustainable engineering during his USC studies.

“I enrolled at USC because it gave me the opportunities and connections to kick off my research career in sustainable innovations in civil engineering,” he said.

“I found the experience challenging, exciting and extremely rewarding.”

He said highlights included presenting at conferences to a variety of audiences.

“I will never forget travelling to Australia at the start of my candidature. The Sunshine Coast is quite different to Lockerbie in Scotland! I am grateful that I saw the USC campus before the pandemic hit, and although I only managed two weeks in Australia, I have every intention to return.”

Finn said the findings of his thesis confirmed his initial thoughts.

“There is room for new and disruptive technologies in civil engineering, like waste plastics in roads,” he said.

“If this technology was adapted worldwide, I believe we would see significant CO2 reductions and a viable way of off-setting plastic waste without compromising road performance.”

Finn, who worked in Lockerbie for international plastic roads company Macrebur while he was studying, now works at Aecom and lives in London.

Dr White said remote student supervision was not unusual for USC’s pavement research program.

“Many of our research students have selected USC for access to supervising academics with specialised pavement engineering backgrounds,” he said.

“Since 2015 we have supervised students from the UK, the Middle East and New Zealand, as well as students based in Sydney, Melbourne and Canberra.”