Researchers from the University of Sheffield and Stellenbosch University are working together to combine 3D Concrete Printing (3DCP), a new construction method, with Geopolymer Concrete (GPC) technology to create safer wall panelling in housing in economically challenged communities in South Africa.
South Africa faces a critical housing shortage, with over 2.6 million low-income households (LIH’s) lacking government-subsidized units. The LIH units, often built with traditional materials like concrete and burnt-clay bricks, suffer from poor construction quality, high maintenance costs, and inadequate thermal performance. Furthermore, the production of cement, a key component of concrete, is energy-intensive and contributes significantly to carbon emissions.
South Africa also faces a major challenge with coal ash disposal. The country generates 40 million tonnes of fly ash annually from its coal-fired power stations, but 90% of that - 36 million tonnes - ends up in landfills. This poses a significant pollution risk and wastes valuable land.
The groundbreaking initiative, funded by The Royal Society, is led by University of Sheffield academics: Dr Behzad Nematollahi, Lecturer in Concrete Technology, and Dr Mehdi Chougan, Research Associate in 3D Concrete Printing along with Prof Jacques Kruger, Extraordinary Associate Professor of Structural Engineering at Stellenbosch University, and aims to address these challenges by developing the 3D-printed, low-carbon concrete wall panel system for rapid, high-quality, and sustainable LIH construction.
This system leverages 3DCP to minimize waste and accelerate construction while enhancing quality. It incorporates GPC technology, which is a cement-less alternative to conventional concrete, with the potential to reduce carbon emissions by up to 80%.
Dr Nematollahi, Project Lead, said: “The groundbreaking nature of this project lies in its ability to tackle both challenges simultaneously by combining 3DCP and GPC technologies. While there are other universities in the UK that are conducting research on 3DCP using conventional cement-based materials, our work specifically targets the 3D printing of GPC, which sets us apart. This innovative approach not only reduces the carbon footprint of construction materials but also aims to lower costs, making it more accessible for applications such as affordable housing.”
Prof Kruger, Project Co-Lead, said: “Stellenbosch University is the leading 3DCP institution in Africa equipped with facilities to print large-scale wall elements and test their full-scale structural and thermal performances. This capability allows us to bridge the gap between laboratory-scale innovation and real-world application, ensuring that the proposed interlocking wall panels meet both performance and economic criteria.”
Keep up to date with the project via the ‘Prefabricated 3D-printed low-carbon concrete wall panels for low-income housing construction in South Africa’ website.