CalX

For more than three years, CalX has been conducting research and development in close collaboration with leading scientific partners including IFREMER and the CNRS. This work has led to the development of Oysteria, a 100% natural marine concrete designed as an alternative to conventional marine concrete. Made from recycled oyster shells used as mineral aggregates and a clinker-free natural hydraulic binder, Oysteria is engineered to be both structurally relevant and ecologically compatible. It is intended for applications such as reef restoration, coastal protection, aquaculture supports, offshore ecological structures, and other maritime infrastructure requiring durability in marine environments. The technology is currently at around TRL 4–5, with laboratory validation completed and real-world marine testing underway.

Since July 2025, CalX has been testing around 50 formulations in real sea conditions, notably in partnership with marine research actors, to assess mechanical resistance, setting behavior, durability under immersion, and biological colonization capacity. Early results show strong ecological potential, with significantly enhanced biological capture compared with conventional concrete.

Alongside this deeptech activity, CalX is building a short-term industrial model based on the valorisation of oyster shells into powders and flakes for agriculture, plastics, construction materials, and other industrial sectors. To support this deployment, CalX is implementing a pilot shell processing unit in Gujan-Mestras, at the heart of the Arcachon Bay oyster farming area. This facility will process up to 1,500 tonnes of oyster shells per year and is strategically located just 5 km from the shell resource, ensuring a highly local, low-logistics, circular supply chain. The unit will perform washing, drying, crushing, and grading operations to transform shell waste into marketable mineral resources while securing the raw material supply needed for future Oysteria production.

Through this dual model, CalX combines immediate industrial traction with long-term breakthrough innovation. The company aims to create local value, reduce waste, decarbonize materials, and contribute to the regeneration of coastal and marine ecosystems through scalable, science-based solutions.