Concrete is the world’s most widely used construction material, yet its production is responsible for 5-8% of global CO2 emissions, mainly due to clinker manufacture. With more than 4 billion tonnes of cement produced annually, the sector emits approximately 2.7 billion tonnes of CO2 per year, making it a major barrier to achieving the Paris Agreement target of limiting global temperature rise to well below 2 °C. These challenges are even more critical for marine infrastructures, where sustainability and durability issues converge. Coastal and offshore structures suffer from severe chemical attack, microstructural deterioration and accelerated corrosion due to chloride-, sulphate- and magnesium-rich environments. Meanwhile, freshwater and natural aggregates-traditionally required for concrete-are scarce on islands and many coastal regions, especially in Europe where nearly half the population lives within 50 km of the sea. To reduce environmental pressure while supporting Europe’s extensive maritime infrastructure, there is growing interest in using seawater and industrial by-product supplementary cementitious materials (SCMs) to produce low-carbon concrete. Early studies suggest that seawater ions can accelerate hydration of silicate and aluminate phases, while SCMs improve long-term durability and reduce clinker demand. However, the combined chemo-physical effects of seawater ions and SCMs remain poorly understood, limiting safe and widespread adoption. Furthermore, without a durability-integrated life-cycle assessment (LCA), industry and policymakers lack the evidence needed to implement such materials in design standards and coastal construction.
The LCMMCMs project aims to develop Low-Carbon Multi-Component Marine Cementitious Materials with high durability and reduced environmental footprint for coastal and offshore infrastructure. The project’s scientific and technological objectives are:
(1) Unravel the ion-specific effects of seawater on hydration and structural evolution of cement components.
(2) Quantify and optimise the synergistic interactions between seawater ions and SCMs, enabling tailor-made, high-performance marine binders.
(3) Determine the mechanical performance and long-term durability of LCMMCMs under realistic marine exposure.
(4) Develop a durability-coupled LCA model to assess environmental and economic impacts throughout their service life.
(5) Train the Fellow as an independent leader in sustainable marine construction materials through a multidisciplinary programme integrating experiments, simulations, engineering and industry applications.
Together, these objectives address four scientific challenges: ion-dependent hydration (SC1), seawater-SCM interactions (SC2), long-term service performance (SC3) and life-cycle sustainability (SC4).
