Researchers have found a way to put mountains of glass waste to good use: turn it into a concrete that’s superior to traditional varieties made from dwindling sand resources.
No doubt you think you’re helping the planet when you throw your glass bottle into the yellow bin, instead of the red one.
But there’s a good chance it ends up as waste in the dump, rather than recycled. New revelations show that hundreds of thousands of tonnes of glass are being sent to landfill.
As depressing as this is, researchers from the University of Melbourne have found one way to put glass waste to good use.
They’ve discovered that glass can be used instead of sand – to create top quality prefabricated concrete panels for commercial and residential construction.
This is a relief, considering the world is running out of sand, due to its over-extraction.
The search for a viable replacement may be born out of necessity, but it’s lead to a superior product. The team has created a concrete that’s cheaper, stronger and more lightweight than traditional concrete that’s made from sand, fly ash, slag and other supplementary materials.
“Our work has shown it has excellent sound, thermal insulation and fire-resistant characteristics,” researcher Dr Ali Kashani told The Fifth Estate.
“We are looking forward to working with the cement and concrete industries and building standard regulators to prove the viability of using these products in traditional concrete structures,” he said.
Researchers are currently experimenting with glass percentages of 10 to 30 per cent and they’re confident that higher quantities could be used.
But Australia’s codes are blocking progress in this area. For large percentages of glass to be used, an engineer must sign-off on it. Researchers want building standards to be revised to allow more glass to be used in concrete production on an industrial level.
Not only would this preserve a scarce resource (sand) by putting a waste product (glass) to good use, it could also lead to fewer carbon emissions. Waste glass can be used to create geopolymer cement, which is one solution put forward by a recent report that says zero carbon cement is a real possibility.
Over in Switzerland, researchers are getting their inspiration from the trees, as they use wood to make concrete greener and lighter.
They’ve stumbled upon a way to produce a load-bearing concrete that can contain more than 50 percent of wood. This product has good flame retardancy, thermal insulation and it’s suitable for prefabricated units.
However, more testing needs to be done. It could be many years before glass and wood are used to make concrete for construction purposes, but if that day comes to pass, it will no doubt revolutionise the industry.