July 20, 2021

...AND CHEAPER...:

Using plastic waste to help solve sand shortages (Bernd Debusmann Jr, 7/20/21, BBC)

To try to reduce the need for sand, a small but growing number of researchers are turning to technology and innovation in the hunt for alternatives.

These include Dr John Orr, a lecturer in concrete structures at Cambridge University. His research has found that plastic waste can be sorted, cleaned, shredded and crushed into a sand alternative for use in concrete.

He has looked specifically at the potential impact of the solution in India. Here the cost of sand has skyrocketed - while at the same time estimates suggest that 15,000 tonnes of plastic waste is dumped every day in the country.

"We found that you can replace up to 10% of the sand in concrete with the plastic, and it has the same strength and the same longevity," says Dr Orr.

Unlike sand, plastic won't stick to the cement paste around it, so it can only replace 10% of the raw material, he says. "But that still saves the need for a huge amount of sand, and helps to reduce the vast amount of plastic waste on India's streets.

"From a cost perspective, using the plastic can be cheaper, broadly speaking, especially as sand goes up in price as it becomes more scarce. For countries like the UK this isn't really an issue, as we don't build much, but in nations with a construction boom, using plastic in concrete could grow in popularity."

Dr Orr reckons that if using plastic in making concrete were adopted across India it could save 820m tonnes of sand a year.

At the same time, other research is being done into using other waste materials in concrete in place of sand, such as shredded old car tyres or ground-down glass.

Posted by at July 20, 2021 12:00 AM

  

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