As Africa’s construction sector seeks more sustainable building materials, limestone calcined clay cement (LC³) is emerging as a promising low-carbon alternative to traditional cement. With abundant clay deposits available across much of the continent, researchers and industry leaders are working to overcome technical challenges that will enable the large-scale adoption of this next-generation cement technology.
Chryso Southern Africa is playing a leading role in this transition through research and development aimed at improving the performance and consistency of LC³ across diverse African markets.
According to Mpume Mabaso-Mlalazi, Research and Development Manager at Chryso Southern Africa, while South Africa has traditionally relied on supplementary cementitious materials such as fly ash and slag to reduce clinker content, many African countries have greater access to natural clay resources. This makes calcined clay an attractive solution for lowering the carbon footprint of cement production.
Reducing clinker content has become a key priority for the global cement industry as manufacturers work to cut carbon emissions and meet sustainability targets.
However, the successful adoption of LC³ depends on managing the natural variability of clay deposits, which can differ significantly in mineral composition, fineness, water demand and reactivity.
To address these challenges, Chryso has conducted extensive research on more than 30 different calcined clay samples, developing advanced testing methods to better understand how different clay types interact with chemical admixtures used in concrete production.
One of the company’s proprietary testing methods evaluates polymer intercalation within clay minerals, providing valuable insights into how admixtures perform under varying material conditions.
According to Mabaso-Mlalazi, clay naturally absorbs large amounts of water, making it essential to carefully control water content during concrete production. Excess water can reduce concrete strength, while insufficient water affects workability and placement.
The company also highlighted the importance of managing concrete rheology—the way fresh concrete flows—as this directly influences workability, pumping efficiency and long-term structural performance.
Another technical challenge involves the interaction between clay particles and superplasticisers. Certain clay minerals can absorb chemical admixtures, reducing their effectiveness and forcing producers to increase dosage rates, which raises production costs.
Using insights gained through its research programme, Chryso has developed specialised polymer technologies and customised admixture solutions designed to improve workability, optimise strength development and deliver more consistent concrete performance across different clay sources.
The company believes these innovations will help accelerate the industrial-scale deployment of LC³ by making low-clinker cement systems easier, more reliable and more cost-effective to use.
Industry momentum continues to build following discussions at the International Conference on Calcined Clays for Sustainable Concrete (ICCCSC 2026) held in Cape Town earlier this year, where researchers and industry stakeholders called for greater collaboration to support the commercial rollout of calcined clay cement technologies.
As Africa’s infrastructure and construction sectors continue to expand, innovative materials such as LC³ could play an increasingly important role in reducing carbon emissions while making greater use of locally available raw materials. By combining global research expertise with local application knowledge, Chryso Southern Africa aims to help build a more resilient, sustainable and competitive construction industry across the continent.
