Displaying items by tag: granite

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.

Asia

In Indonesia, Suvo Strategic Minerals has concluded tests with Makassar State University of a novel nickel-slag-based cement. Huadi Nickel-Alloy Indonesia supplied raw materials, and tests showed a seven-day compressive strength of 37.5MPa. Suvo Strategic Minerals says that a partnership with Huadi Nickel-Alloy Indonesia for commercial production is a likely next step.

Europe

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.

Middle East

Talks are underway between UK-based calcined clay producer Next Generation SCM and City Cement subsidiary Nizak Mining Company over the possible launch of a joint venture in Riyadh, Saudi Arabia. The joint venture would build a 350,000t/yr reduced-CO₂ concrete plant, which would use alternative cement based on Next Generation SCM’s calcined clay.

North America

Texas-based SCM developer Solidia Technologies recently patented its carbonatable calcium silicate-based alternative cement, which sequesters CO₂ as it cures.

Meanwhile, C-Crete Technologies made its first commercial pour of its granite-based cement-free concrete in New York, US. C-Crete Technologies says that the product offers cost and performance parity with conventional cement, with net zero CO₂ emissions. Its raw material is globally more abundant than the limestone used as a raw material for clinker. Other abundantly available feedstocks successfully deployed within C-Crete Technologies’ repertoire include basalt and zeolite.

Across New York State, in Binghamton, KLAW Industries has succeeded in replacing 20% of concrete’s cement content with its powdered glass-based SCM, Pantheon. KLAW Industries has delivered samples to local municipalities and the New York State Department of Transportation. Its success expands the discussion of possible circular cement ingredients from the industrial sphere into post-consumer resources.

In Calgary, Canada, a novel SCM has drawn attention from one of the major cement incumbents: Germany-based Heidelberg Materials. It invested in local construction and demolition materials (CDM)-based SCM developer EnviCore on 9 October 2024. The companies plan to build a pilot plant at an existing Heidelberg Materials CDM recycling centre.

Conclusion

Alternative cement developers are still finding the words to talk about their products. They may be more than ‘supplementary’ up to the point of entirely supplanting 100% of clinker. Product webpages offer ‘hydraulic binder,’ ‘pozzolan’ and even ‘cement.’ As alternative ‘cements’ are developed, they build on the work of pioneers like Joseph Aspdin and Louis Vicat. Start-ups and their backers are now reaching commercial offerings, on a similar-but-different footing to cement itself. None of these novel materials positions itself as the sole, last-minute ‘super sub’ in the construction sector’s confrontation with climate change. Rather, they are a package of solutions which can combine into a net zero-emissions heavy building materials offering, hopefully before 2050.

Related to this is the need for ‘technology neutral’ standards, as championed this week by the Alliance for Low-Carbon Cement and Concrete (ALCCC), along with 23 other European industry associations, civil society organisations and think tanks. The term may sound new, but the concept is critical to the eventual uptake of alternative cements: standards, the ALCCC says, should be purely performance-based. They ought not attempt to define what technology, for example cement clinker, makes a suitable building material. According to the ALCCC, Europe’s building materials standards are not technology neutral, but instead ‘gatekeep’ market access, to the benefit of conventional cement and the exclusion of ‘proven and scalable low-carbon products.’

At the same time, cement itself is changing. Market research from USD Analytics showed an anticipated 5% composite annual growth rate in blended cement sales between 2024 and 2032, more than doubling throughout the period from US$253bn to US$369bn. If you can’t beat it, blend with it!

For a further discussion of alternative cement and binders in Europe, see Global Cement’s interview with ALCCC co-ordinator Joren Verschaeve in the forthcoming November issue of Global Cement Magazine on 17 October 2024.

US: C-Crete Technologies has poured its granite-based cement-free concrete in its first construction application at the upcoming JPMorgan Chase headquarters at 270 Park Avenue, Manhattan. Ecology, Environment and Conservation News has reported that the concrete generates no net CO₂ emissions by sequestering atmospheric CO₂ in its curing process. The concrete conforms to ASTM International standards, with a compressive strength exceeding 5000psi. Other partners on the project included engineering firm Severud Associates Consulting Engineers and construction management firm AECOM Tishman.

C-Crete Technologies president Rouzbeh Savary said "We are thrilled to introduce our new granite-based concrete at such a prestigious and iconic location. The building at 270 Park Avenue is set to become a landmark not only for its architectural grandeur, but also for its sustainable construction practices."

Severud Associates Consulting Engineers senior associate Fortunato Orlando said "The performance of C-Crete for concrete on metal deck, topping slabs, pavements and landscape work, coupled with its eco-friendly attributes, makes it a revolutionary product for the future of the construction industry."

AECOM Tishman chief operating officer John Kovacs said "Just a few years ago, constructing devoid of Portland cement and CO₂ emissions would have seemed unimaginable. And yet today, we stand as the world's first, setting new thresholds of what's possible in sustainable construction. We thank all of our partners on this project and look forward to the day when CO₂ emission-free construction is not simply an idea or a new innovation, but the industry standard across every build."