Supplying Sizewell C: How LKAB Minerals’ Limestone filler supports major UK infrastructure – in partnership with Heidelberg Materials UK
As the UK continues to invest in major infrastructure projects to meet energy, environmental, and economic goals, reliable and high-quality materials are essential for project delivery. LKAB Minerals is proud to play a supporting role in this transformation, working in partnership with Heidelberg Materials to supply Limestone filler for Sizewell C – one of the UK’s most important low-carbon nuclear power projects.
Why Limestone filler matters
Concrete is one of the world’s most used building materials – and one of the most carbon-intensive to make. That’s because cement, a key ingredient in concrete, contains a lot of clinker, which releases CO₂ when produced.
By adding Limestone filler to the mix, we can reduce the amount of clinker needed. It’s a small change with a big impact.
Since 2023, UK standards have allowed up to 20% Limestone filler in concrete. That’s opened new opportunities to make construction more sustainable without losing strength or performance.
Here’s what Limestone filler brings to concrete:
- Lower emissions: Reduces the clinker content, cutting CO₂ from cement production.
- Better workability: Helps concrete flow and compact more easily.
- Improved finish: Creates smoother surfaces with fewer pores.
- Consistent quality: Maintains strength and performance over time.
- Cost efficiency: Uses less cement, helping manage material costs.
On projects as large as Sizewell C, where thousands of cubic metres of concrete are poured, those benefits make a real difference.
Supporting responsible construction
Together with Heidelberg Materials, we’re helping to build more environmentally responsible concrete for the UK’s energy future. Milling and supplying Limestone filler for nuclear construction may sound like a small part of a huge project, but it plays an important role in lowering carbon and ensuring long-term durability.
We also think about what happens beyond production. Our Limestone filler can be supplied in bulk or bagged formats, and our silo recovery and recycling services help customers minimise waste and keep sites clean. It’s all part of creating a more circular, efficient way of working.
Reliable supply, consistent quality
Our Gurney Slade quarry has supplied Limestone to UK industry for generations. Today, it’s one of several sites that form our national production network. Having multiple supply points means we can deliver the right material where and when it’s needed.
Quality matters just as much as logistics. Every batch of Limestone filler is checked through our in-house laboratory and XRF testing to ensure consistent composition and performance.
Our Limestone filler typically contains at least 70% calcium carbonate, with a maximum moisture content of 1% and a bulk density between 0.5 and 0.9 Mg/m³. These properties make it well-suited for both concrete and asphalt applications.
We also comply with BS EN 7979 and BS EN 13403 standards, so our customers can rely on every delivery.
Looking ahead
Sizewell C marks another step in the UK’s shift toward cleaner, more secure energy. Working with Heidelberg Materials, we’re proud to contribute to a project designed to last for generations. As the construction industry continues to look for lower-carbon, high-performance materials, limestone filler will play an increasingly important role.
If you’d like to learn more about our Limestone filler or talk about how it could support your next project, get in touch with our team. You can also follow us on LinkedIn for the latest updates, case studies, and product releases!
