Science & Technology (Commonwealth Union) – The rapid growth of urbanization in the last few decades has seen an increased demand in urban spaces.
As cities become more crowded and skilled construction labour is increasingly difficult to find, the industry faces growing pressure to complete projects more quickly, efficiently, and with fewer workers on site. Over the last ten years, 3D concrete printing (3DCP) has emerged as a potential answer to these challenges because of its high level of automation and its ability to operate without traditional formwork. Even so, in Singapore its use has so far been restricted mainly to non-structural building applications.
Researchers from the College of Design and Engineering (CDE) at the National University of Singapore (NUS) have now shown that 3D concrete printing can move beyond those limits. Led by Senior Lecturer Dr Du Hongjian and Associate Professor Pang Sze Dai from NUS CDE’s Department of Civil and Environmental Engineering, the team demonstrated that 3DCP can produce structural building components that are more sustainable, require less material, and reduce on-site labour, while still satisfying structural performance standards. For the construction sector, this could translate into faster delivery timelines, reduced reliance on manpower, and greater design flexibility for modular construction.
To ensure the technology can function in practical construction settings, the research was conducted in partnership with construction company Woh Hup. It was supported by the Building and Construction Authority (BCA) and the National Additive Manufacturing Innovation Cluster (NAMIC), a national platform hosted by the Agency for Science, Technology and Research.
Making 3D concrete printing suitable for structural applications can be key advantage for the construction industry. 3DCP allows builders to create complex forms without formwork and with very little manual input. However, technical constraints mean that most real-world uses today are limited to non-structural features or low-rise buildings — applications that do not align well with the needs of land-scarce, high-density cities such as Singapore.
The NUS researchers focused on a practical issue: how to use 3D concrete printing (3DCP) on structural parts. Their method combines traditional building methods with 3D printing that doesn’t require formwork. This lets them make structural parts with more design freedom and better use of materials.
They worked on two important parts that are necessary for real-world use: the concrete mix and the building process. The team designed printable concrete that is easy to extrude, stable enough to build, strong enough to support itself, and works with current structural production systems.
At the same time, they created a fabrication workflow that fits within current prefabrication and on-site construction practices, ensuring the printed components are not only structurally sound but also practical for large-scale manufacturing and installation.
Using both laboratory experiments and full-scale trials, the researchers evaluated how reinforced 3DCP structural elements perform under load. The findings showed these components can meet required strength standards while using far less material than conventional designs. The automation process sharply lowered the dependence on manual labour as well, with industry evaluations showing manpower savings going above 40 percent and efficiency enhancements of over 60 percent for complex parts. The result is quicker construction, lower workforce requirements, and more reliable project timelines.
Formwork-free printing removes that constraint, allowing for more adaptable designs and faster production. Estimates further suggest that 3DCP can cut material use by about 30 percent compared with conventional construction methods.
“Construction innovation only matters if it can be applied on site,” explained Associate Professor Pang. “Working directly with industry partners enables us to test these technologies against real constraints and build confidence for wider adoption. We hope to continue in this partnership with BCA and the Built Environment (BE) industry to further improve these technologies, to bring about even greater gains in productivity.”
Mr Yong Derong, Executive Director, Woh Hup indicated that putting a test on the novel technology beyond the lab makes it possible for all parties to make specific practical constraints and opportunities to enhance the productivity and lower manual labour in the construction sector.
