Chisom Ekomaru
Sustainability Manager
Susan McGarry
Director Public affairs and Sustainability
As Ireland accelerates its net zero commitments, some of the most effective solutions already exist, particularly in construction, one of the country’s most carbon-intensive sectors. Concrete is the second most consumed material after water. However, its primary binder, traditional cement, is a major source of greenhouse gas emissions.
Cement and the global carbon challenge
Despite representing only 15% of concrete’s volume, cement accounts for over 90% of its embodied carbon. In Ireland, cement production was responsible for approximately 5% of national emissions in 2022. The most effective strategy for reducing these emissions is to substitute clinker, cement’s most carbon-intensive component, with lower-carbon alternatives.
Industrial circularity and clinker substitutes
Transitioning the construction sector requires upcycling industrial byproducts. For over 25 years, Ground Granulated Blast Furnace Slag (GGBS) – a steel industry byproduct and Ecocem’s first commercial product – has served as a primary clinker substitute. This material significantly lowers the carbon footprint of concrete while maintaining structural durability.
Ecocem’s technology has supported major infrastructure projects including Le Grand Paris Express, Dublin’s Aviva Stadium, the Paris 2024 Athletes’ Village, and the UK’s HS2. These landmark developments prove that low-carbon solutions can meet the most rigorous structural and safety requirements of modern engineering.
As Chisom Ekomaru, Sustainability Manager at Ecocem, notes, “By transforming industrial by-products into high-performance cement, we cut carbon at the source and enable our customers to meet their climate commitments with scalable low-carbon solutions, reducing reliance on costly downstream fixes.”
As the steel industry shifts toward Electric Arc Furnace (EAF) technology, the profile of available byproducts is changing. Along with a consortium of partners, Ecocem is leading a research programme supported by the European Innovation Council Pathfinder, to optimise EAF and Basic Oxygen Furnace (BOF) slags for low-carbon cement production.
New breakthrough cement technology – ACT
Ecocem is preparing to bring ACT to the market. The first globally scalable cement technology capable of delivery rapid, cost-effective decarbonisation to the cement industry. Developed through extensive R&D, ACT uses widely available materials and existing infrastructure to reduce cement’s carbon footprint by up to 70%.
In 2025, Ecocem introduced more than €220 million of investment in new production capacity and R&I facilities to accelerate the commercialisation of ACT. This investment includes €50 million for its first production facility at Dunkirk, increasing ACT capacity to over 1 million tonnes per year by 2026, and €170 million to build four new production lines in France – ensuring that the next generation of low-carbon cement is available at the scale required for global decarbonisation.
The first globally scalable cement technology capable of delivery rapid, cost-effective decarbonisation to the cement industry
Policy and removing barriers
The European Commission identifies clinker substitution as a high-readiness, cost-effective solution. However, barriers remain, including regulatory lag, where materials like recovered glass are still classified as “waste,” and standardisation processes that don’t yet recognise these circular inputs.
Susan McGarry, Director of Public Affairs and Sustainability emphasises, “Public policy is crucial to accelerating low-carbon cement adoption. Ireland has shown leadership by mandating 30% clinker replacement in publicly funded projects, the first EU country to do so. Building on this with greater ambition and alignment with proven technologies can drive deeper emission cuts. To fully realise circular innovation at scale, regulatory frameworks and standards must keep pace with technological progress, providing clear and efficient pathways for high-performance, low-carbon materials to reach the market.”
