Materials

Carrots n' beets used to strengthen concrete

Carrots n' beets used to stren...
The enhanced concrete contains nano-platelets derived from carrot and beet root fibers
The enhanced concrete contains nano-platelets derived from carrot and beet root fibers
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The enhanced concrete contains nano-platelets derived from carrot and beet root fibers
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The enhanced concrete contains nano-platelets derived from carrot and beet root fibers

It was just back in April that we heard about how scientists had made concrete stronger and more eco-friendly by adding graphene to it. Now, researchers at Britain's Lancaster University are reporting that they've achieved even better results using less-expensive "nano platelets" derived from root vegetable fibers.

The proof-of-concept study is being led by Prof. Mohamed Saafi. He tells us that the cellulose-based platelets (which were produced in collaboration with Scottish firm CelluComp) are basically "nano sheets synthesized from carrot and sugar beet root." Those vegetables were obtained as waste products from the food industry.

When added to a traditional concrete mix (cement, aggregate and water), the platelets increase the amount of calcium silicate hydrate – it's the main product of the hydration of widely-used Portland cement, and is chiefly responsible for the strength of concrete.

In lab tests, adding the platelets made concrete significantly stronger, to the point that 40 kg (88 lb) less Portland cement per cubic meter of concrete was required in order to achieve the same strength as would otherwise have been possible. This means that less concrete would need to be used in any given structure, which is important to the environment, as cement production is a large source of manmade carbon dioxide emissions.

Additionally, adding the platelets was found to boost the density of the concrete's microstructure, which would allow structures to last longer by being more resistant to corrosion. As a result, those structures wouldn't need to be replaced as often, further reducing the amount of cement required by the construction industry.

"The composites are not only superior to current cement products in terms of mechanical and microstructure properties, but also use smaller amounts of cement," says Saafi. "This significantly reduces both the energy consumption and CO2 emissions associated with cement manufacturing."

The scientists are also looking into creating thin nano platelet-based sheets, which would be applied to the outside of existing structures made from traditional concrete. The sheets could increase the lifespan of those structures, by providing additional strength.

Source: Lancaster University

4 comments
David
Would the material properties of concrete benefit from the addition of fibres made from shredded plastic, specifically the type of plastics that cannot be recycled.
christopher
The reason they said 40kg instead of 1.6% is because 40kg sounds like a lot, until you learn that one cubic meter of concrete is 2.4 tonnes.
voluntaryist
Why strive to keep the same strength? Why not test the stronger concrete to see if rebar can be eliminated? Also, why not make it waterproof? Doesn't moisture eventually deteriorate? If it was waterproof wouldn't that mean no added moisture barrier would be needed? Using a unique blend of minerals in the mix also strengthens by a factor of 5 times, e.g., Grancrete.
Of course, if the consumer only cares about initial cost and not durability, then none of this matters.
Who will innovate, if it means taking a risk that exceeds benefit? Most thinking is very short term, due to the chaos of politics.
nehopsa
Christopher: exactly. My point. I also noticed. I am upset with this manipulative reporting. 40 kg out of 2400 kg saved!? Give me a break. Saving the Earth, of course....
On the other hand, more durable material is cute - even if with this style of reporting I have no idea what "resistant to corrosion" really means here. Is it less rusting rebar? Is it less concrete spalling? Or something different still?