Researchers at the University of the Free State (UFS) are helping to shape the future of construction technology after successfully designing and building a large-scale concrete 3D printing system entirely in-house – a significant achievement that positions the university at the forefront of advanced digital construction and sustainable infrastructure research in South Africa.

Developed by the Green Concrete Lab under the leadership of Dr Hossein Naghizadeh in the Division of Ecological Engineering, the facility represents far more than a new piece of equipment. Every component of the system – including the mixing and pumping systems, robotic integration, monitoring and control systems, software, and data acquisition platform – was independently developed by the UFS research team.

Prof Vasu Reddy, Deputy Vice-Chancellor: Research, Innovation and Postgraduate Studies, expressed praise for this achievement: “This achievement exemplifies outstanding research-led innovation with tangible impact. This is a pioneering example of locally anchored technological capability that advances South Africa’s position in digital construction. This is a project that is smart and most important, a cost-saving innovation.”

According to Dr Naghizadeh, the project grew from a vision to develop local engineering solutions rather than relying solely on imported technologies.

“In 2019, I participated in a landmark project at the University of Johannesburg, where South Africa’s first 3D-printed house was constructed,” he says. “The project demonstrated the enormous potential of digital construction technologies, but it also highlighted the challenges associated with importing large-scale 3D printing systems, including high costs for equipment, software licences, maintenance, training, and materials.”

“At the same time, we recognised the strong technical and engineering expertise available at the University of the Free State. This inspired us to ask an important question: why should South Africa rely entirely on imported solutions when we have the capability to design and build our own?”

By developing the system internally, the team achieved an estimated saving of approximately R6 million while simultaneously building advanced technical expertise among researchers and students.

Driving innovation through local engineering expertise

Dr Naghizadeh says the turning point came during ecological engineering research focused on algae-based wastewater treatment systems.

The team was developing green concrete and biochar composites to remove contaminants from wastewater when they encountered a major challenge: conventional casting methods could not produce the complex bio-inspired reef structures needed for efficient treatment performance.

“Concrete 3D printing has opened entirely new possibilities by allowing us to fabricate intricate geometries that would otherwise be impossible or extremely costly to manufacture,” says Dr Naghizadeh.

“At that moment, we understood that this technology had the potential not only to transform our research, but also to position the UFS and South Africa at the forefront of advanced digital construction and sustainable infrastructure innovation.”

The printer operates similarly to a desktop 3D printer, but on a significantly larger scale and using specially designed concrete materials instead of plastic. A digital model is created using advanced software before the concrete mixture is prepared in a continuous mixer and pumped through a controlled delivery system to a robotic arm fitted with a printing nozzle. The robot then builds structures layer by layer with high precision.

“What makes the process particularly exciting is that it allows us to create complex shapes and customised structures that are extremely difficult, expensive, or even impossible to produce using conventional construction methods,” he explains.

One of the biggest technical challenges was developing the integrated smart mixer-pump system, which is regarded as the core of the technology.

“Our team brought together experts from civil engineering, materials science, mechanical engineering, electrical engineering, and digital systems to design an integrated smart mixer-pump system from scratch,” says Dr Naghizadeh. “The result is a highly adaptable research platform with advanced monitoring and control capabilities that, in many respects, performs beyond the flexibility offered by many commercial systems.”

“It is so clear that our scholars have truly demonstrated what breaking down silos mean. They have shown that by working across disciplines in collaborative teams, it is possible to create new ways of solving problems together, “ remarked Prof Reddy.

Preparing students for the future of construction

Beyond its research value, the facility has become a powerful training platform for postgraduate students, interns, and young researchers.

Students were directly involved in the design, fabrication, testing, and operation of the system, while also developing expertise in printable materials and digital modelling processes.

“Students involved in the project are developing highly specialised skills in areas such as digital construction, robotics, concrete 3D printing, automated systems, advanced materials design, and digital modelling,” says Dr Naghizadeh.

“These are scarce and future-oriented skills that will become increasingly important as the construction industry moves towards automation, sustainability, and smart infrastructure technologies.”

He believes that early exposure to emerging technologies is essential for the next generation of engineers and construction professionals.

“The construction industry is undergoing a major technological transformation driven by automation, digitalisation, and sustainability,” he says. “Future engineers and construction professionals will need to work with advanced technologies such as robotics, digital fabrication, and smart construction systems.”

The facility is capable of producing a wide range of concrete elements – from structural components and architectural features to specialised hydraulic structures and artificial reef systems for wastewater treatment applications.

Dr Naghizadeh says concrete 3D printing also holds major sustainability benefits, because it reduces material waste and minimises the need for traditional formwork and support structures.

“Because the material is placed only where it is structurally needed, the process allows for more efficient use of resources and optimised structural designs,” he explains.

He adds that technologies such as concrete 3D printing could eventually help address infrastructure and housing challenges in South Africa by enabling faster, smarter, and more sustainable construction solutions.

“This achievement demonstrates the exceptional interdisciplinary research and engineering capability that exists at the UFS,” says Dr Naghizadeh. “It shows that UFS researchers and students are able to conceptualise, design, and develop world-class technologies locally, while addressing real societal and industrial challenges.”

For Prof Reddy, “the concrete 3D printing system is an innovation that extends beyond construction into ecological impact. It has direct and positive bearing on improving societal grand challenges. Why? This technology can support faster, more sustainable building and helps address housing and infrastructure needs. It also provides our students with hands-on skills, thereby building a pipeline of future innovators in a rapidly evolving technological landscape.”