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Concrete. It’s everywhere. Even if you can’t see it. Modern society is built on it. But at what cost? 

Concrete is used in huge amounts. Even steel structures need concrete in their foundations. It’s very difficult to do any kind of civil engineering job without some concrete being involved. But it’s very damaging to the environment. It produces huge amounts of CO2 when manufactured, so has a massive carbon footprint. 

So, what can be done to improve the sustainability of concrete? To reduce its carbon footprint and help tackle climate change?  

Our Senior Lecturer in civil engineering materials and Head of the School of Civil Engineering and Surveying, Dr Stephanie Barnett is looking at ways to make concrete stronger, longer-lasting and more sustainable. In the process she hopes people will start to appreciate this material more.

Stephanie says, ‘I think we’d be hard pressed to live without concrete. There is nothing that can compete in terms of the amount of it that we get through. Everybody thinks it’s grey and boring. I’d like people to see the complexity under the surface.’

Made to last

Instead of looking at alternative materials to concrete, Stephanie thinks there are ways to reduce concrete’s CO2 impact. 

Cement is the glue that holds concrete together. And it’s the bit that does the damage. Stephanie suggests more work is needed on the design of concrete mixes. More efficient use of cement could make a big difference.

Performance of the concrete itself is key to Stephanie’s research. She’s looking at ways to make concrete last longer. Which in itself will reduce overall CO2 emissions.

‘If you can make a building stand up for 150 years without maintenance, then you’ve got something that is more sustainable. We need to think about the whole lifecycle of the building. Rather than just the CO2 that goes into building the building.’

One way Stephanie is hoping to achieve longevity is through her research on steel fibre reinforced concrete. She explains: 

‘Concrete is quite a brittle material. There are a lot of things that make it crack. Steel fibres are very good at reducing that cracking, and helping the concrete to maintain some integrity when it’s cracked. So it holds it together, even when it’s damaged. Fibre reinforced concrete also increases a structure’s blast resistance, increasing inhabitants’ safety.’

Embracing this stalwart of the built environment, and making it the best it can be, will help to make our built environment more sustainable.