From Shopping Bags to Streets: Turning Plastic Waste into Infrastructure

Global plastic waste is projected to exceed one billion tonnes a year by 2050. Yet only about nine per cent is currently recycled. Researchers at Edith Cowan University (ECU) now suggest that common household plastics, such as shopping bags and milk bottles, could be transformed into stronger and more sustainable roads.

Repurposing Plastics for Pavements

PhD researcher Ali Ghodrati explains that adding waste plastics to asphalt improves both the environment and road quality. Recycled plastics can increase durability and extend the lifespan of road surfaces. At the same time, they divert waste from landfills and oceans, reducing the pressure of plastic pollution.

Plastics have been used in road construction since the 1990s to improve resistance and stiffness. Using recycled plastics instead of virgin materials, however, lowers carbon emissions and decreases reliance on new raw resources.

Methods and Material Performance

ECU’s Dr Themelina Paraskeva describes three ways to add plastics to pavements: wet, dry and hybrid methods. Wet methods blend plastics directly with bitumen. This improves compatibility and lowers the risk of microplastic release. Dry methods are simpler but may cause uneven distribution and faster wear. Hybrid approaches aim to balance efficiency with sustainability.

Not all plastics work in road construction. Thermoplastics from shopping bags and milk bottles melt at 140–180°C, the same range used in asphalt production. These materials mix well with bitumen without extra energy or harmful by-products.

Sustainability and Challenges

Roads made with recycled plastics fit within the circular economy. They reuse and repurpose waste, cut greenhouse gas emissions and reduce maintenance costs. Yet challenges remain. High concentrations of plastic can make asphalt brittle. There are also environmental risks, including fumes, leaching and the release of micro- and nano-plastics during use.

While small-scale trials are promising, researchers stress the need for more testing. Roads must be assessed under different climates and traffic conditions to prove long-term safety and performance.

Towards Circular Infrastructure

For architects, urban planners and landscape designers, this innovation shows how waste can become a valuable resource. Recycled plastic roads are an example of circular design principles at work, offering practical and durable infrastructure while tackling one of the world’s most urgent environmental challenges.

Source: Edith Cowan University
Photo: Markus Spiske