Infectious Diseases

Concrete made with shredded PPE gear offers up to 22% higher strength

Concrete made with shredded PPE gear offers up to 22% higher strength
RMIT scientists have developed concrete that features shredded PPE gear for a boost in strength
RMIT scientists have developed concrete that features shredded PPE gear for a boost in strength
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RMIT researcher Shannon Kilmartin-Lynch with his team’s concrete made with shredded forms of PPE
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RMIT researcher Shannon Kilmartin-Lynch with his team’s concrete made with shredded forms of PPE
RMIT scientists have developed concrete that features shredded PPE gear for a boost in strength
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RMIT scientists have developed concrete that features shredded PPE gear for a boost in strength

Scientists continue to make promising inroads around more durable forms of concrete, and engineers at Melbourne's RMIT University have been operating at the cutting edge of this research for some time. Their latest example simultaneously tackles the mounting waste generated by the ongoing pandemic, demonstrating a form of concrete that incorporates shredded personal protective equipment (PPE) for improved performance.

RMIT's researchers haven't been afraid to get creative when thinking up new approaches to concrete, turning to everything from tires, to lobster shells to steel slag for inspiration. Last year, they also showed how disposable face masks could be worked into stronger recycled concrete aggregate for road layering.

This time around, the team has expanded their work to include other waste products of the coronavirus pandemic. According to the researchers, an average of around 54,000 tonnes of PPE is produced globally each day, and around 129 billion disposable face masks are discarded around the world each month. Their research may have uncovered a new way to give these materials a second life.

Across three studies, the team incorporated shredded gowns, rubber gloves and face masks into concrete at different concentrations, ranging from 0.1 to 0.25%. The rubber gloves were found to boost compressive strength of the concrete by up to 22%, while the face masks improved it by up to 17%. The shredded gowns, meanwhile, improved compressive strength by 15%, elasticity by 12% and resistance to bending stress by up to 21%.

RMIT researcher Shannon Kilmartin-Lynch with his team’s concrete made with shredded forms of PPE
RMIT researcher Shannon Kilmartin-Lynch with his team’s concrete made with shredded forms of PPE

"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. "With a circular economy approach, we could keep that waste out of landfill while squeezing the full value out of these materials to create better products – it’s a win on all fronts."

From here, the team aims to investigate the performance benefits of mixing the different PPE items together, and to collaborate with the health and construction industries as they work toward field trials.

“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 landfill,” said Dr Rajeev Roychand, co-lead author of the study.

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

Source: RMIT

6 comments
6 comments
Eric Blenheim
They should add sea water as well, ancient Roman concrete structures are still intact today due to the strength sea water adds.
Aross
Hopefully they will look at the effects of the tiny dust particles that will come off the concrete as it wears away. Will this add to the micro plastics problem?
Username
The problem is like with all repurposing/recycling ideas is that there is no actual supply of the material. There is no collection system in place to gather used PPE. they are in landfills (and unfortunately in water ways and everywhere else).
@Eric Blenheim Portland cement doesn't handle salt and neither do the rebars.. Romans used a different ciment made with volcanic ash in a now lost recipe.
DaveWesely
"Waste not, want not" is not a bad design philosophy. PPE is mostly disposable plastic fabric and latex. The upside to its reuse is that it is a relatively clean and known material, unlike a lot of the dreck that ends up in the trash. But as far as keeping material out of a landfill, I don't understand the logic. The problem with waste polluting the environment is not due to landfills. It is due to waste not ending up in landfills.
Modern landfills keep dreck out of the environment. Wood and plastic are excellent waste products in that they are inert or decay slowly, creating a safe carbon sink. Glass, metal and concrete can be reused. Organic (food) waste should be composted for reuse as topsoil. In a landfill it only creates runoff and methane.
There is no shortage of landfill space. Making it a scapegoat only encourages alternative disposal methods in ditches, rivers, and oceans.
Evets
Why do "scientists" and "engineers" from today's universities insist on using concrete as the dumping ground for whatever happens to be the world's latest unwanted garbage? And why then are they credited for coming up with some kind of new, cutting edge, planet saving discovery? As someone who's worked in the real world concrete industry for almost 4 decades, I consider this to be about as worthless as other recent "breakthrough" methods for producing concrete such as replacing sand or aggregate with ground up rubber or plastic. Same thing with the industry standard use now of replacing portland cement with fly ash and ground granulated blast furnace slag. It's always the same line from the "experts", "equal or higher in strength and with improved workability" translates into "I've never finished concrete a day in my life." They also fail to mention the toxic elements they're introducing into the new and improved concrete, like arsenic and mercury just to name a couple.
MAN
One of the probable issues is durability.
With time the PPE wastes will degrade and thus the strength will probably be different. Size of the schred is also not clearly specified but it seems that it is cm order; if confirmed, the evolution over time of the degradation of the schredded PPE will become a real issue for the overall strength and homogeneity of the concrete.