It’s been rather boldly called the wonder material for the 21st century, and one of
the biggest scientific developments of recent decades.
Incredibly strong, flexible and conductive despite being just one atom thick, graphene
created quite a stir when it was properly discovered back in 2004.
Then, the possibilities seemed endless, and construction was one of the areas set to benefit, with
space elevators and record-breaking skyscrapers made from graphenated composites
among the early predictions.
But nearly 20 years later, it’s fair to say those prophecies were just a bit wide of the mark,
and you’d be forgiven for thinking that graphene was nothing more than a load of hype.
But you’d be wrong. Because now, that long-awaited moment
where graphene finally finds its way into construction has arrived.
For thousands of years, new materials have come along and transformed the way we build.
It’s happened with everything from wood and stone to concrete and steel, but it’s
been some time since something completely disrupted this industry.
Enter graphene: a material that has been seemingly about to take over the world for years, that’s
now in with an actual real chance of joining this prestigious club. Yes, really.
Before we go any further, it might be useful if we told you what graphene actually is.
It’s where carbon atoms are bonded together in a hexagonal lattice - a bit like honeycomb
- and it’s this arrangement that’s largely what makes graphene so special.
Another material with a similar name and structure is graphite, which you’ll know as the stuff
that goes in pencils. With graphite, these lattices are positioned in layers.
Strip graphite down to just one atomic layer and you’re left with graphene. This means
it’s two-dimensional, giving it some pretty unique properties.
It’s 200 times stronger than steel by weight, lighter than paper, it’s super-flexible
and the most conductive material of both electricity and heat ever discovered.
You’re probably now realising why it generated so much excitement when it was first discovered.
But in the years that followed, all that initial enthusiasm began to fizzle out.
Innovators couldn’t figure out how to make the stuff in bulk, which is necessary to create
actual products - ones that offered real, noticeable improvements. Until now.
Let’s get to the point then and stop stringing you along.
How is graphene now being applied in construction, and is it making much of a difference?
Initially, graphene research into materials over the past decade has been composite materials,
coating materials, membranes, for example, but we’re seeing a big shift into construction materials.
Dr Lisa Scullion is Application Manager at the Graphene Engineering Innovation Centre,
or GEIC - based at the University of Manchester in the UK.
You can increase the strength of your material - concrete, for example - in such a way that
you can actually use less concrete.
What we’re seeing when we put graphene into concrete is we get huge amounts of early strength
- so we get very, very high tensile strength -
in the first few days of the concrete curing.
We get less water ingress, less corrosive iron ingress into the concrete,
so it’s really multi-functional.
In May 2021, Nationwide Engineering, in partnership with the GEIC, became the world’s first
construction firm to lay a graphene concrete slab in a commercial setting - for a new gym
that’s being built near Stonehenge.
To make its new product, Concretene, the company put tiny amounts of graphene into what is
otherwise a fairly standard concrete mix, strengthening the material by around 30%,
and giving it anti-cracking properties too.
Crucially, it can be used just like normal concrete, without the need for extra training
or equipment when mixing or laying it.
Companies like Nationwide - they’ve taken a big risk actually constructing with graphene concrete.
Obviously there’s lots of regulations around concrete and the industry doesn’t necessarily
move very quickly and I think that because they’ve started to take risks other people
are wanting to take those risks too.
In fact, they already are. 3D-printed, graphene-enhanced concrete is set to be deployed on one of the
world’s biggest infrastructure projects, HS2 – the UK’s second high-speed rail scheme.
For the main line out of London Euston, parts of the retaining walls will be made from concrete
that’s 3D-printed by machines.
Microscopic strands of graphene will be applied to the mix, making the material so strong
that no steel reinforcement will be needed.
Replacing rebar doesn’t just mean less material; it can make sites safer, offer more flexibility
and save time, which is just what’s needed on a project that’s been more than a little controversial.
Elsewhere in the world of transport, graphene has already proven to be an effective additive
for surfaces like roads and runways.
At Rome’s Fiumicino Airport, a new type of graphene-enhanced tarmac has been trialled,
which its creators claim is twice as long-lasting as regular asphalt.
Developed by Iterchemica, the material, called Gipave, combines graphene with a special type
of plastic that is not normally recycled.
It has also been used on roads, including one in Oxfordshire.
Here, a 750-metre stretch was upgraded with the material to make it much less likely to
crack in cold and wet weather.
That’s what leads to potholes - one of the few things guaranteed
to send a British person into a full-blown rage.
As well as being used to increase strength, graphene can be mixed into liquid coatings
which are then applied to structures for a specific purpose, like preventing corrosion.
Chinese firm The Sixth Element Materials found that adding just 1% of graphene to one of
its coatings allowed it to reduce the amount of zinc used by 65% - that’s another material
that can be harmful to the environment.
When applying the coating to steel bridges and wind turbines built around sea water,
which is what causes the corrosion, they found it could last twice as long as regular formulas.
It’s all being made possible by rapid progress on the production side.
Now we’ve got to the point where there’s lots of different graphene producers, there’s
ways to make it at scale that are cost effective.
Now the supply chain’s there, we know if we want to make a huge concrete structure
we can get enough graphene of the right grade to use for that structure and that’s been
one of the big drivers I think.
While these case studies aren’t quite on the same scale as the mad concepts we showed you
at the beginning, they are signs that graphene could finally be realising its potential in
this most critical of industries.
I’d say in the future, short term - maybe in the next five years - we’ll still be
at a similar stage using graphene in construction because we have to deal with
industry regulations and such things.
But going forward I think that now people realise the potential there will be a whole
raft of different applications and products that come out of this.
We might have to wait a bit longer to build that space elevator, although that’s
clearly a challenge this ‘wonder material’ was never really going to solve on its own.
In the meantime, all eyes will be on graphene once again to see where it goes next - at
least this time there’s a solid foundation to build on.
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