The idea of billions of people going through a few masks a week during this pandemic definitely rings alarm bells, but a team of researchers in Melbourne may have the solution.
They've discovered that adding millions of discarded face masks to road-paving (铺路) mixtures would actually lower the cost of the road, while preventing billions of them from landfills. Just one kilometer of road would need three million masks, and the polypropylene (聚丙烯) plastic used to make single-use surgical face masks also increased the flexibility and durability of the road.
The new material is a mixture of about 2% torn masks, with recycled concrete aggregate (RCA)—a material obtained from waste concrete and other minerals from destroyed buildings. This recycled material was found in the study to be ideal for two of the four layers generally required to create roadways. Paving a kilometer of two-way road with the RCA and three million face masks would result in a change of 93 tons of waste from landfills.
The final product then is more resistant to wear than asphalt (沥青), as well as being cheaper too, provided there was a method for collecting masks. The research team did a cost-analysis and found that, at $26 per ton, the RCA was about half the cost of mining raw materials, and as much as a third of the cost of shipping the used masks to a landfill.
The widespread application would be ideal for large infrastructure (基础设施) projects. For example, Washington has the 11th worst roads in terms of unaddressed repairs in the U.S. If the damaged roads in Washington state were repaired with the RCA/mask mixture, it would reuse nearly 10 billion masks, sparing American landfills hundreds of millions of tons of trash.
It's said that the team is looking for private industry partners or governments willing to give their plastic mask road an opportunity for a large-scale test.