A team of scientists in the UK have developed a low-carbon construction material using desert sand that could take pressure off increasingly scarce natural resources.
The group from Imperial College London have invented a composite material called Finite that is as strong as concrete, but has half the carbon footprint, and is fully biodegradable.
Desert sand has remained an untapped resource as its wind-swept grains were previously too fine to be used as filler in concrete.
Post-graduate students Carolyn Tam, Matteo Maccario, Hamza Oza and Saki Maruyami came together to create a building material that could be made from a plentiful, naturally occurring material.
“We looked at sand because we thought sand was abundant, but actually when we did more research about sand [we found] it wasn’t,” Tam told Dezeen.
Sand scarcity is a global issue
Far from being an infinite resource, the world is looking at a crisis-level sand shortage in the not-to-distant future – hence the start-up’s name, Finite.
At Dutch Design Week a symposium was held to discuss the sand crisis, which will affect glass-making and computer chip manufacturers as well as concrete suppliers.
To make concrete you traditionally need larger-grained sand that’s been tumbled by water. Concrete is in high demand for construction as city-building booms.
“Sand is the most consumed resource on earth after freshwater,” Dutch design duo Atelier NL told Dezeen at the time.
Sand-mining is a multi-billion dollar industry, and illegal sand mining plagues countries such as India, where criminal gangs plunder riverbeds and beaches, damaging local ecosystems.
“The wars that are going on for sand throughout the world, all these things were crazy to us when we found out,” said Maccario.
Finite uses abundant resources
Finite could change that. The binder ingredients are a guarded secret, but the scientists are confident that it outperforms concrete on key sustainability metrics.
“The main binder in concrete is responsible for five per cent of global CO2 emissions, which is huge,” said Maccario.
“Our worst-case estimate right now is less than half the CO2 footprint than concrete, in terms of what we are using,” continued Maccario.
As well as being low-carbon and taking the strain off current sand sources, Finite is much more reusable than concrete, which often ends up in landfill.
“If you make a block of it in the future it’s quite easy to recycle and not use any virgin material, whereas concrete needs to be essentially ground up and then used as filler for the next batch of concrete,” explained Maccario.
Material suited to short-term infrastructure projects
Finite is non-toxic and can be left to decompose naturally, or remoulded to be used in another project.
“We could use the material to make pavilions, then after three months when the event ends it can be deconstructed safely,” said Tam.
The team believe their material is ideal for use in the Middle East as the raw material for the concrete alternative can be scooped straight out of the desert, rather than being expensively imported.
Theoretically, Finite could also be used for permanent structures such as residential projects, but for this it would need to pass rounds of testing and regulations.
New materials bring new opportunities
Early experiments with resin casting have demonstrated that the material can also be used to create objects such as vases and bowls. Left untouched, Finite takes on the colour and gradation of the filler, but natural dyes can be added in the mixing process.
Cost-wise, Maccario is confident that Finite will be a viable competitor to concrete in the construction industry once it is manufactured on a larger scale, because of the abundance of the raw materials.
For the moment, the scientists are focusing on getting funding for their start-up. The Imperial Enterprise Lab is supporting the team in its Venture Catalyst Challenge.
“It will take more than just our project or one material, but we’re really looking forward to is a future where the built environment isn’t this thing where you keep it there forever or landfill it or down-cycle it, but something that uses nature and is continuously reusable,” added Maccario.
“As soon as you have new materials you have new opportunities.”
Atelier NL has been creating glass samples from region-specific sand they crowd-sourced, in order to demonstrate that beautiful glassware doesn’t necessarily need to come from a limited pool of white sand quarries. As part of his thesis project, Edinburgh College of Art student Peter Trimble built a portable machine that could build furniture from sand, urine and bacteria.
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