Cementing a reputation
Bringing a low-carbon cement to market.
Danielle Dawson from Holcim UK
© HolcimAs demand grows for lower-carbon construction materials and concerns increase around the long-term availability of traditional raw materials, the cement industry is under pressure to diversify its formulations. In response, we are continuing to explore new cementitious solutions that reduce carbon impact while maintaining performance and scaleability.
One such development is our new low-carbon cement, designed as a sustainable alternative to traditional Portland cement (PC). The formulation is predominantly composed of clinker and gypsum, with recycled concrete fines (RCF) blended in. Recycled concrete fines, which would otherwise be a waste product from demolished buildings, partially replaces clinker in the cement.
As clinker is the most carbon-intensive component of cement production – due to the high temperatures required during manufacture – reducing its proportion in a cement blend significantly lowers the overall carbon footprint.
The innovation behind this product lay not in inventing a new technology, but in validating and adapting an established European approach to UK regulatory and performance standards.
Prior to our trials, Holcim Switzerland pioneered the use of cement containing RCF in 2019. This reduces the clinker content and its CO2 emissions by 10% compared to an already CO2-optimised Swiss mass cement.
Following the successful demonstration of a ready-mix pour at Holcim UK’s Whetstone plant, we know that cement that has 20% of the clinker replaced with RCF shows no loss of production feasibility.
The manufacturing of this particular cement follows the same standard process as any other cement production, except RCF must go through additional crushing and processing before it can be ground and blended into the mix. While the cement doesn’t require a specific type of recycled concrete, the chosen source material must meet EN 197-6 requirements.
The success of this trial means we are well on the way to having another viable replacement to PC on the market soon, ready for future construction projects. The next stage is to undergo further testing and certification, before this CEM II-classified product can then be written into the revised British Standards for concrete, BS 8500.
Trial pouring of concrete made with recycled concrete fines-based cement
© HolcimRCF is currently permitted in cement under EN 197-6, but is not yet harmonised with BS 8500 for ready-mix applications. The next revision of BS 8500 is due in 2027.
Our current findings show that these cements broadly perform comparably to limestone-based cement CEM II A-L (binary), which is covered by EN 197-5 and was incorporated into the UK national annex BS 8500 in 2023.
Holcim UK is now actively acquiring construction demolition materials (CDM) businesses – recent firms purchased include Land Recovery, Thames Materials and P.J. Thory Ltd – to secure further circular raw material streams in-house.
In doing so, Holcim UK is creating a fully circular supply chain by integrating demolition material businesses with our cement production capacity. The logistics chain for this low-carbon cement will include CDM businesses collecting and crushing waste concrete, which is then processed into fines, transported to our cement plants and blended into CEM II A-F.
These waste streams will be put back into future production at our new cement works in Tilbury, which is currently in-build and will look to be operational from late 2026. Scale-up will then begin once testing, approvals and plant readiness align.
Since we have already acquired the businesses needed to set up an efficient sourcing and processing chain, we are well on the way to bringing this cement to UK customers.
