Displaying items by tag: supplementary cementitious materials

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."

Canada: Heidelberg Materials has invested in EnviCore, a Canada-based startup that is developing low-carbon solutions. Together, the companies will focus on increasing the use of recycled construction and demolition materials as supplementary cementitious materials (SCM). This collaboration includes planning a pilot SCM production facility near one of Heidelberg Materials' recycling hubs, pending an upcoming feasibility study. Heidelberg Materials has also acquired a minority stake in EnviCore.

Katharina Beumelbur, chief sustainability and new technologies officer and member of the managing board of Heidelberg Materials, said “EnviCore’s novel approach has the potential to unlock new possibilities of increasing the amount of recycled materials we use in our products. This could pave the way to further reduce our need for virgin materials, contributing towards preserving valuable natural resources and protecting our environment.”

Ireland: Mannok, Sweden-based minerals company Boliden and the South Eastern Applied Materials (SEAM) research centre at South East Technological University in Carlow, Wexford and Wicklow in Ireland have launched a 30-month project to reduce the embodied CO₂ emissions of cement. The project will investigate possible uses of shale as a supplementary cementitious material (SCM) in cement production and the CO₂ curing of cement paste-based mine backfill. Enterprise Ireland has supplied funding worth €700,000 for the collaboration.

Mannok operations director Kevin Lunney said "We are delighted to be working with SEAM and Boliden on this critical research for the cement sector, which could have many far-reaching benefits for the construction sector more generally. Finding local, viable, low-carbon solutions for the industry can make a major contribution to lowering emissions in Ireland."

Boliden specialist development engineer Adam McElroy and section-mill process head Colum Burns said "This project will greatly enhance our knowledge and understanding of the potential for developing low carbon cement for mine backfill purposes and for utilising backfill systems as a carbon sink. The project will also investigate synergies between the cement manufacturing and mining industries that could enhance the sustainability of both industries."

Australia: Zeolite, kaolin and metakaolin producer Zeotech has appointed James Marsh as its new CEO, effective from 9 September 2024. Current CEO Scott Burkhart will then transition to chief operating officer. The appointment is intended to support Zeotech’s entry into large-scale production of high reactivity metakaolin for use in cement and concrete.

Marsh is a director of Australian Kaolin. He previously worked as executive director sales and marketing at Andromeda Metals, after holding managerial roles at multiple minerals companies. He has a bachelor’s degree in Chemistry and Physics from the University of the West of England, UK.

Managing Director Peter Zardo said "James' technical experience in the industrial mineral and cement industries, especially metakaolin, will be pivotal in accelerating Zeotech's goal of becoming a significant supplier of premium supplementary cementitious materials. Queensland-based leadership is critical to achieving the Company's objectives as we ramp up work programmes and industry engagement, and James will play an essential hands-on role in executing Zeotech's strategy."

James Marsh said "I'm excited to join Zeotech at a crucial stage of the company's strategy, where I can utilise my experience and connections to make it a significant player in decarbonising the construction industry."

The National Development and Reform Commission and other government bodies in China released plans this week to cap clinker production capacity at 1.8Bnt/yr by the end of 2025. Energy efficiency of existing capacity will be used as the driver to determine which production lines can remain open. 30% of capacity will be required to be above the benchmark energy efficiency level. Plants below this line will be obliged to upgrade or face elimination.

Points of interest from the longer release include detail on how the authorities intend to promote energy efficiency. Installing improved production line equipment is as might be expected. However, there is also a drive towards low-carbon fuel substitution such as an increased thermal substitution rate (TSR) through the use of alternative fuels (AF), promotion of renewable energy sources and, interestingly, no new cement plants will be able to add captive coal power plants. The government is targeting a TSR of 10% by the end of 2025 with 30% of lines using AF in some form or another. A plan to reduce the clinker factor in cement is also being pushed through for the increased use of blast furnace slag, fly ash, carbide slag, manganese slag and other supplementary cementitious materials. This last point might have big implications for the ferrous slag export market but that’s a story for another day.

Working out how much these new measures will affect the cement sector in China in the short term is not straightforward since it’s unclear what the country’s actual production capacity is and how much of it is actually active. Data from the National Bureau of Statistics of China showed that cement output was 2.02Bnt in 2023. The China Cement Association (CCA) estimated that the capacity utilisation rate was 59% in 2023. So, if the sector were using all of its integrated cement plants flat out, then one might crudely suppose that the national production capacity might be around 3.5Bnt/yr. This guess does not take into account the prevalence of blended cements and a whole host of other factors so should be treated with caution. Given that cement output fell by 5% year-on-year in 2023, output could be just over 1.8Bnt in 2025 if the rate of decline holds. Research by Reuters in April 2024, suggested that the capacity utilisation rate hit 50% in that month, suggesting that the sector could meet the target in 2024 if it’s a particularly bad year. So, provided the production cap is enacted along the same lines of peak-shifting, where plants are temporarily shut for periods, then the target looks well within reach.

As reported in April 2024, the Chinese cement sector has faced rationalisation in recent years as the real estate market collapsed. Output peaked in 2020 and then fell subsequently. Most of the big producers endured falling sales volumes, revenue and profit in 2022, although some managed to resist the continuing decline in 2023. One coping mechanism has been to focus on overseas markets as proposed by the government’s Belt and Road initiative. Huaxin Cement has been a particular proponent of this strategy. The CCA says that China-based companies have invested in and built 43 clinker production lines in 21 countries with a cement production capacity of 81Mt/yr. Another 43Mt/yr of capacity is currently being built outside of China with yet another 25Mt/yr of capacity proposed for construction.

It is interesting, then, to note that the CCA issued an official warning this week to its members to invest ‘cautiously’ in Uzbekistan. The association said in a statement that at the end of April 2024 the country had 46 integrated production lines with a cement production capacity of 38Mt/yr. This is double the country’s demand for cement. Half of this production capacity is managed by China-based companies. It added that the utilisation rate was currently 50%, that the price had dropped by about 40% since 2020 and that competition was ‘fierce.’ Incredibly, another 7Mt/yr of capacity is expected to be added in 2024. The CCA has advised Chinese companies to consider the state of the Uzbek cement market before making any more investments.

The two news stories we have explored this week cover two sides of the same issue: Chinese cement overcapacity. The local market is finally slowing down after a period of phenomenal growth and the big question is what is the actual market demand now that all the big stuff has already been built. The government gives every impression it is using the decline to meet its sustainability goals. Like institutions in many other places it has set itself targets that it seems likely to meet. The flipside of overcapacity at home is investment overseas. China-based plant equipment manufacturers have certainly done well out of this situation. Yet in Uzbekistan, at least, it looks like the cement sector in China has also managed to export its overcapacity. This has created the absurd situation where the CCA has implored its members and others to exercise the same self-discipline abroad that the government extols at home. Another way to put this might be that Chinese cement companies are increasingly unable to make money at home… or in Uzbekistan. This then leaves a query over where else enthusiastic Chinese cement investors may be causing market imbalances. One solution might be for the Chinese government to impose a cap on clinker production by its companies outside the mainland. Whatever happens next though, the introduction of a capacity cap in mainland China marks a decisive change to the local cement sector.

Germany: France-based Fives has won a contract to build a 50t/day clay calcination unit at Rohrdorfer’s Rohrdorf cement plant in Bavaria. The unit will integrate into the plant’s clinker line in order to allow it to test the production of limestone calcined clay cement with up to 40% reduced CO₂ emissions. Fives’ clay calcination unit uses a flash calcination process, based on a three-stage preheater, flash calciner and decolourisation system.

Rohrdorfer’s Net Zero Emissions Labs team is responsible for the project to decarbonise the Rohrdorf cement plant by 2038. Its managing director Helmut Leibinger said “After a detailed technical review, we decided that the flash calciner with an integrated clay calcination unit from Fives FCB was the best solution in terms of reliability, efficiency and colour control. We are confident that the unit will be essential in moving forward on our pathway to net zero.”

US: St Marys Cement won three national awards at the Slag Cement in Sustainable Concrete Awards 2023. The producer won the awards for supplying its slag cement for the construction of Wixom Assembly Park in Wixom, Michigan; of 333 North Water in Milwaukee, Wisconsin, and of Excellerate Manufacturing in Appleton, Wisconsin.

Netherlands: EMC Cement and HES International plan to build a 1.2Mt/yr plant in Amsterdam to produce an alternative cement that contains 70% volcanic ash. The cement will also include recycled concrete fines. Production will be carbon neutral and consume 90% less energy than traditional ordinary Portland cement production. The Amsterdam plant is scheduled for commissioning by early 2026.

EMC Cement CEO Atle Lygren said "Our EMC Technology, by replacing 70% of Portland cement clinker, enables significant climate action without the need for costly carbon capture and storage, aligning with the demands of the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change."

France: NeoCem plans to build a €50m clay calcination plant at Saint-Maximin, Picardy. The company recently raised €23m in investments in its Series A funding round. The Le Journal des Enterprises newspaper has reported that the Saint-Maximin plant will enter operation in 2025, and will subsequently grow to 200,000t/yr in capacity. NeoCem aims to employ 100 people by 2030.

Head of industrial deployment Guillaume Luu said “To be used in concrete, limestone must be heated for several hours at 1400°C. Our clay-based binder generates CO₂ emissions of 120kg/t, compared to almost 1000kg/t of limestone binder, and our technology can transform all types of clays available. The idea is not to open new quarries, but to give a second life to materials already on the surface." He continued “The up-cycling of clays and their transformation into a low-carbon binder addresses several challenges for the construction sector. On the one hand, the reuse of clay waste, and on the other hand, the decarbonisation of the building materials sector.”