Carbon Negative Cement From Ultra-Mafic Rocks

Portland cement production is a major global source of CO₂ emissions resulting both from the chemical decomposition of limestone and the high-temperature, fossil-fuel-dependent production process.

Concerto addresses the climate impact of traditional cement by developing a novel, low-carbon alternative: a hydraulic binder based on magnesium-silicate (silico-magnesian) minerals. CNRS has developed a groundbreaking, scalable process for producing silico-magnesian cements from ultramafic rocks eliminating the CO₂ emissions from limestone calcination.

The innovative manufacturing process has the potential to become fully electrified. If produced with decarbonized energy, this cement can achieve a net-negative carbon footprint through carbonation.

Ultramafic rocks, the primary raw material, are abundant in accessible surface deposits within coastal ophiolite belts, facilitating straightforward mining and efficient transportation. The resulting cement formulation is non-irritant and fast hardening, making it immediately suitable for specialized applications such as tile adhesives, radioactive waste storage and 3D printing or precast elements. These properties provide a strong foundation to expand its market into broader construction applications.

This research ultimately aims to develop a scalable and cost-competitive binder that directly tackles the climate impact of construction. The core ambition is to deliver a high-performance, durable cement with a radically low carbon footprint, thereby creating a truly sustainable alternative to Portland cement.