Engineers at Stanford University are investigating the viability of recycling waste plastic into large-scale infrastructure projects such as roads and buildings.
As part of the study, the engineers looked at already-completed projects, such as the repaving in 2020 by California Department of Transportation (Caltrans) on a section of Highway 162 using recycled asphalt pavement and liquid plastic made from single-use plastic bottles. According to a departmental report, that was the first time Caltrans paved a road using 100 percent recycled materials.
Another project under scrutiny was the façade panelling on the San Francisco Museum of Modern Art, which used fibreglass-reinforced plastic to create a rippling effect.
Stanford engineer Zhiye Li said the study highlighted the issues concerning the economics and logistics of managing plastic waste streams from municipal solid waste.
“Plastic waste material flow is highly variable”, Li said.
“Its mass can change from month to month, as can the type of plastic – lots of different packaging, for example”, she added.
Currently, they are specifically considering fibreglass-reinforced polymer composite, a tensile plastic commonly used in car, boat and plane parts, rather than domestic or municipal waste, since plastic materials differ widely and only some can be used for specific purposes.
The study concluded that when effective waste sorting systems are widely available, transforming large masses of plastic waste into major infrastructure projects should be viable.
Image: Caltrans
