One unusual thing about coverage of cement in the media is the way that discussions often centre precisely on its absence – that is, on alternatives to cement. These alternatives boast unique chemistries and performance characteristics, but are all produced without Portland cement clinker. They are generally called ‘alternative cements,’ perhaps because ‘cement-free cement’ does not have such a commercially viable ring to it. This contradictory tendency reached a new high in the past week, with developments in alternative cement across Asia, Europe, the Middle East and North America. Together, they hint at a more diverse future for the ‘cement’ industry than the one we know today.
Cement producer Mannok and minerals company Boliden partnered with the South Eastern Applied Materials (SEAM) research centre in Ireland to launch a project to develop supplementary cementitious materials (SCMs) from shale on 7 October 2024. The project will additionally investigate CO2-curing of cement paste backfill for use in mines. Irish state-owned global commerce agency Enterprise Ireland has contributed €700,000 in funding.
UK-based SCM developer Karbonite expects to launch trial production of its olivine-based SCM with a concrete company in 2025. The start-up launched Karbonite Group Holding BV, with offices in the Netherlands, to facilitate this new phase. Karbonite’s SCM is activated at 750 – 850°C and sequesters CO2 in the activation process, resulting in over 56% lower CO2 emissions than ordinary Portland cement (OPC). Managing director Rajeev Sood told Global Cement that talks are already underway for subsequent expansions into the UAE and India.
Back in the UK, contractor John Sisk & Son has received €597,000 from national innovation agency Innovate UK. John Sisk & Son is testing fellow Ireland-based company Ecocem’s <25% clinker cement technology in concrete for use in its on-going construction of the Wembley Park mixed development in London.
At the same time, Innovate UK granted a further €3.23m to other companies for concrete decarbonisation. Recipients included a calcined clay being developed by Cemcor, an SCM being developed from electric arc furnace byproducts by Cocoon, a geopolymer cement technology being developed by EFC Green Concrete Technology UK and an initiative to develop alternative cement from recycled concrete fines at the Materials Processing Institute in Middlesbrough. Also included was the Skanska Costain Strabag joint venture, which is working on the London stretch of the upcoming HS2 railway. The joint venture, along with partners including cement producer Tarmac and construction chemicals company Sika UK, will test low-kaolinite London clay as a raw material with which to produce calcined clay as a cement substitute in concrete structures in HS2’s rail tunnels.