Paving the way for ultra-low carbon concrete: Flex350

A major transformation is underway, as September’s BSI Flex350 update has opened the door to the ultra-low carbon cement that the industry is looking for, according to Paul Beswick, innovation development manager at Material Evolution.

Here, Paul elaborates on how the new code of practice enables ultra-low carbon concrete to be specified for use in construction projects, why this is a major milestone in our collective journey towards more sustainable building practices, and the tremendous potential for all stakeholders involved – including developers, contractors, architects, engineers and green material manufacturers, like Material Evolution.

Building on solid foundations

Prior to September 2024, BS EN206 and BS8500 had been the only documents that dictated what could and couldn’t be called concrete, the materials it could be made of and in what situations it could be used

These standards were based on many years of testing and hundreds of years of evidence of using concrete in practice – in other words, solid foundations. As the second most common material on the surface of the earth – used in buildings, bridges, schools and almost every structure on the planet – it remains incredibly important that the guidelines are watertight. Material failure would be catastrophic, making specifiers naturally risk averse.

While necessary, these standards didn’t allow for anything new, making it difficult for those championing modern, ultra-low carbon cement and binders for use in concrete. Cement accounts for 8% of global CO2 emissions and imposes an enormous environmental cost – a fact that the industry has woken up to in recent years, and one that it’s keen to address.

Why Does Flex350 Matter?

Last month, the Institute of Civil Engineers (ICE) and cross-industry UK Lower Carbon Concrete Group (LCCG) worked to accelerate the decarbonisation drive by publishing a new version of Flex350.

As a performance-based code of practice, Flex350 sets a stringent cement and concrete testing procedure that must be carried out, to ensure that new, truly lower carbon cements can be used safely within concrete. This means that those materials not previously covered by British standards can now be more readily considered, which will help all stakeholders to specify, build with, and gain access to ultra-low carbon concretes for construction projects.

This is a huge step forward. Having worked in the industry for many years, I can feel the excitement from peers and the wider industry around the opportunity this presents. There’s a real appetite for sustainable cement and concrete among specifiers – evidenced by the fact that engineers at ICE have spearheaded its adoption – and for the first time, we can legally deliver this.

A step change for Material Evolution

Cement and concrete pose the most significant sustainability challenge to the construction industry, which is why we’re delivering cement with up to 85% less CO2 emissions compared to traditional OPC binders. But our mission doesn’t stop there – as we look to the future, we want to deliver cement with zero carbon emissions on an even larger scale, and to continue innovating as much as possible.

Our current product meets the criteria set out by Flex350, meaning the main regulatory barrier to the widespread adoption of sustainable cement and concrete has been removed from the mix.

Furthermore, it means the adoption of ultra-low carbon concrete will undoubtedly grow, and this update helps to bridge the gap between innovation in material science and practical application in construction, ultimately leading us towards a stronger future for the environment.

Milestone moment

The specification of ultra-low carbon concrete and cement, made possible by the introduction of Flex350, represents a turning point in the construction industry. It signals a growing recognition that sustainability can – and must – be integrated in projects and that specifiers are eager for its arrival.

At Material Evolution, we’re proud to be at the forefront of this movement, offering green cement solutions that help build an ultra-low carbon future. With the barriers removed, there’s nothing stopping us from creating a built environment that is safe, efficient, and durable for both our people and our planet.

If you’re interested in finding out more about our high performance, ultra-low carbon engineered binders, head to our website for updates or get in touch with us at info@materialevolution.co.uk.