Sunday, December 10, 2023

Used masks and gloves can be recycled to make stronger concrete

The use of single-use nitrile gloves and masks has been on a sharp incline since the Coronavirus pandemic first started in late 2019. This led to a significant increase in the generation of this clinical waste that requires various recycling solutions to reduce its environmental impact from disposal or incineration.

Engineers at Melbourne’s RMIT University use disposable personal protective equipment (PPE) to make concrete stronger, providing an innovative way to significantly reduce pandemic-generated waste.

Researchers have not been afraid to get creative in developing new concrete-based materials. For inspiration, they used everything from tires and lobster shells to other types of waste. Last year, RMIT’s researchers also showed how disposable face masks could be recycled into stronger concrete aggregate for road layering.

This time, scientists decided to make concrete by incorporating other waste generated after the coronavirus pandemic. According to researchers, an estimated 54,000 tonnes of PPE waste is produced on average globally each day, and about 129 billion disposable face masks are thrown away every month around the world. Their research may have opened up a new way to give these materials a second life.

In three separate feasibility studies, the RMIT team first shredded disposable face masks, rubber gloves, and isolation gowns and then incorporated them into concrete at various volumes, between 0.1% and 0.25%. The rubber gloves increased compressive strength by up to 22%, while the face masks increased compressive strength by up to 17%. Meanwhile, isolation gowns increased resistance to bending stress by up to 21%, compressive strength by 15%, and elasticity by 12%.

“We have all seen disposable masks littering our streets, but even when this waste is disposed of properly, it all ends up in landfill,” said Professor Jie Li, the corresponding author and research team leader. “With a circular economy approach, we could keep that waste out of the landfill while squeezing the full value out of these materials to create better products – it’s a win on all fronts.”

Researchers now plan to evaluate the potential for mixing the PPE streams, develop practical implementation strategies and work towards field trials. The team is keen to collaborate with the healthcare and construction industries to further develop the research.

“While our research is in the early stages, these promising initial findings are an important step towards the development of effective recycling systems to keep disposable PPE waste out of the landfill,” said Joint lead author Dr. Rajeev Roychand.

The three studies are published in the journals Case Studies in Construction Materials, Science of the Total Environment, and Journal of Cleaner Production.