Cement replacement
We target the cement in the mix, rather than replacing sand or other low-value aggregates.
MATERIALS FOR A DIFFERENT FUTURE
Carbon sinks,
at scale.
Engineered biochar that reduces cement use and stores biogenic carbon in concrete. Designed for the production lines you already use.
Discover the technology A small addition. A lasting difference.
A vision for the built world.
Conceptual architecture
Conceptual architecture
SUPPORTED BY
Conception X
Legal support
Canopy · CISL
Cambridge Enterprise Ventures
Innovate UK Business Connect
Incubator programme
Climate accelerator
Entrepreneurial programme
Entrepreneurship support01 / THE TECHNOLOGYDesigned for the way we build.
Big change.
At the material level.
Concrete shapes our world. We’re changing what goes into it.
Our engineered biochar gives concrete manufacturers two benefits from one additive: less cement used and biogenic carbon stored. It is designed to retain performance and fit into existing manufacturing processes.
Up to20%
Cement replacement
Demonstrated in selected development formulations.
2.32t
CO₂e stored per tonne of additive
Current calculated biogenic carbon storage.
Drop-in
Designed for existing production
Added during the concrete mixing process.
Results depend on feedstock, formulation and application. Cement replacement of up to 20% has been achieved in selected test formulations. The carbon-storage figure is a current calculation; a comprehensive lifecycle assessment and product-specific validation are in development.
From waste to concrete.
Explore the material’s journey.
Select a stage to see how it works.
A new use for residues
Start with what’s left behind.
Agricultural residues and wood waste provide the starting point. These biomass resources can be converted into biochar, giving their biogenic carbon a new material use.
- INPUT
- Biomass residues
- PROCESS
- Feedstock selection
- OUTPUT
- Material for biochar production
01 / 05 Waste feedstock
ENGINEERED BIOCHAR FOR CONCRETE
Why GreenMixes.
Raw biochar has potential. Our functionalisation addresses the handling and performance challenges that stand between that potential and practical use in concrete.
Improved workability
Better workability than untreated biochar in our development formulations.
Improved strength
Improved compressive-strength performance compared with milled biochar in development testing.
Larger particle sizes
Engineered to work with larger biochar particles, expanding the material sizes we can use.
Dust-free product
A dry, dust-free product designed for practical handling and dosing in concrete production.
No pre-soaking
Added during conventional mixing, without a separate pre-soaking step.
Workability comparisons refer to untreated biochar; strength comparisons refer to milled biochar in our development testing. Results depend on feedstock, formulation and application; product-specific validation is ongoing.
02 / REAL-WORLD PROGRESSBuilt on evidence. Moving towards scale.
Out of the lab.
Into the mix.
From tonne-scale production to our completed SOM Innovation Works pilot, GreenMixes is moving into real products. Next: repeatable deployment in pavers and masonry.
20%cement replacement
No sand replaced.
No sand replaced.
Our engineered additive has been incorporated into tonne-scale concrete production, bringing the technology from laboratory batches into pavers and blocks.
Exhibited prototypes from our SOM Innovation Works pilot achieved 20% cement replacement, with no sand replacement, including a carbon-negative brick formulation.
Patent-pending technology, with independent testing and product certification in development. We are building a modular licensing model for biochar producers.
A SMALL ADDITION. A BIG DIFFERENCE.Less cement.
Less cement.
Same familiar mix.
See where GreenMixes fits within the whole concrete mix. A small share of the material can replace a much larger share of the cement.
1.5% of the mixreplaces 10% of the cementUp to 10% · broader applications
Explore your mix with us Example formulation · whole mix by mass
10%of cement replaced
39%indicative CO₂e reduction*
Coarse aggregate45.0%
Sand31.7%
Water7.9%
Cement13.9%
GreenMixes1.5%
CARBON SAVING~112 kg CO₂e*
A SMALL ADDITION37 kg GreenMixesin this 2,400 kg example mix
*Indicative carbon saving. Mix design and application affect performance and carbon impact.
How it’s calculated
These example recipes illustrate proportions, not certified GEN specifications. CEM II describes a cement type; GEN2 and GEN3 describe concrete designations, which do not have one fixed recipe. Each example totals 2,400 kg, assuming equal-mass replacement of cement with GreenMixes.
Carbon estimates use 0.70 kg CO₂e per kg of cement or binder, 30 kg CO₂e for the rest of the baseline mix, and 2.32 kg CO₂e stored per kg of additive. The low-carbon binder option uses an illustrative factor rather than a universal industry value; project claims should use the relevant product EPD. Estimates exclude additional additive processing and transport and are not a completed lifecycle assessment. The SOM brick is a separate formulation.
RECOGNISED FOR
OUR POTENTIAL
03 / BETTER, TOGETHEROne material. Shared opportunity.
The future is
a collective build.
Reduce cement use and introduce stored biogenic carbon into your products. We work with you to develop and test formulations for your feedstocks, equipment and performance requirements.
HOW WE START
- 01Define your product, current mix and performance targets
- 02Develop formulations and agree a representative pilot
- 03Evaluate results and scope product-specific validation
04 / THE PEOPLE BEHIND THE MATERIALCambridge roots. Global ambition.
Researchers.
Builders. Believers.
Bringing together expertise in materials, manufacturing and sustainable construction to turn promising science into practical impact.
Callon Peate
Cambridge Manufacturing Engineering PhD researcher with seven years’ experience in sustainable formulations and supply chains. Leads commercial strategy, partnerships and production scaling.
Dr Dushanth Seevaratnam
Cambridge Chemical Engineering PhD with over a decade’s experience in nanotechnology and sustainable materials. Leads binder development, performance validation and regulatory strategy.
Professor John Orr
Professor of Structural Engineering at the University of Cambridge, leading research in sustainable concrete structures and material-efficient construction.
Paul Larcey
Former Director of Commercial at Lafarge with extensive experience in private equity acquisitions. Advises on new product development, commercial strategy and scaling industrial technologies.
05 / NEWSROOMThe next chapter is taking shape.
Inside GreenMixes.
Milestones, partnerships and ideas in motion.
Selected updates from our LinkedIn.
A stronger foundation for what comes next.
Through The Greenhouse Cohort 10 and the Green Tech Legal Collaborative, we’re building the commercial and legal foundations for partnerships, pilots and our next stage of growth.
Read on LinkedIn
First place at the Cambridge Climate Challenge.
GreenMixes won the Cambridge Climate Challenge 2026, receiving £5,000 and a special award of Canopy membership. Another milestone on our journey from research to real-world impact.
Read on LinkedIn
From lab to market with Conception X.
We’ve joined Conception X Cohort 9, a deeptech venture programme for researcher-founders, to accelerate the journey from materials research to practical applications in construction.
Read on LinkedInFollow the latest from GreenMixes.All updates on LinkedIn