Tomáš Kosa: 3D Concrete Printing will replace certain construction methods

3D concrete printing still seems a bit futuristic and, for many, remains more of a technological experiment. In reality, however, this innovative construction method is gradually establishing itself. The international construction group HSF System is one of the first to actively implement 3D printing into its projects. We spoke with its CEO, Tomáš Kosa, about the benefits and challenges of introducing this technology, and whether it can hold its own alongside conventional construction methods.

HSF System, in collaboration with its subsidiary Coral Construction Technologies, is working intensively on the development of 3D printing technology, and you have already completed several pilot projects. Is this technology ready to compete with conventional construction methods?

This is a completely new technology, so at this stage, every project presents challenges. While the reach of the 3D printer has its limits, its applications are already very broad, and there are essentially two main advantages to 3D printing. One is sustainability—specifically ESG—where, depending on the design, material savings can reach up to 70%; the other is automation. The most demanding part at the beginning is designing the entire structure and creating it in digital models. Due to the specific technology and the machine’s design itself, we segment the printing process; the design of each project is thus completely different, which is why we seek individual solutions in most cases. We consider whether the structure is enclosed or exposed, whether it needs to withstand weather conditions, or what fire safety requirements it must meet. These are issues addressed on a project-by-project basis, so integration into existing projects is currently tailored and requires design preparation. On the other hand, the advantages of this technology are clearly evident in standardized structures or any recurring types of buildings. In the future, we will therefore be able to offer a wide range of standardized prefabricated 3D-printed structures and components. At the same time, in collaboration with the Slovak University of Technology in Bratislava, we are expanding the applicability of 3D printing as a load-bearing structure for single-story and two-story buildings. That is, not only for infill and permanent formwork, but also as a full-fledged load-bearing structure, where we already have the first projects of this type.

However, you are already successfully implementing 3D printing technology in your buildings. What specifically have you completed using this technology so far?

For the Klokan Žilina shopping center, we built six shelters for waste management, where the machine printed directly on-site using delivered ready-mix concrete. These were simple structures that we could replicate. Three people produced the shelters’ supporting structure in essentially less than 10 days, including test samples. If the shelters had been produced using conventional technology, it might have taken just as long, but with more than twice the number of people. This type of structure has already been tested, and we can use it for any future project. Its implementation will therefore proceed very efficiently. In Žilina, we also used this technology to build a car wash, which we designed and printed at our subsidiary, Coral Construction Technologies, in Žďár nad Sázavou. The printed hollow walls were then transported to the construction site, where they were filled with steel reinforcement and poured with concrete. Technologically, we followed the same procedure as in the case of the 3D-printed upper station of the cable car in Kopřivná.

In your opinion, for what type of structure is 3D printing the most ideal technology? Where do you see the greatest potential for future applications?

I’d rather talk about the type of structure. We can print, for example, infill for building facades, partition walls in any type of building, or infill masonry in residential structures. Essentially any partition structure where mechanical strength is required. However, the technology is also ideal for simple structures such as tiny houses, shelters, fire hydrant stations, utility rooms, and guardhouses. The machine can produce any small, self-contained structures entirely on its own.

So do you see 3D printing as an ideal complement to conventional technologies?

Not as a complement, but in the future as a complete replacement for certain structural components or standardized elements that are currently cast from concrete or manufactured using wet processes. 3D printing is simpler and faster. And it’s still concrete, so it’s reliable.

What is currently the biggest obstacle to the wider use of 3D printing in projects? Is it people’s mindset, technological or legislative barriers?

In many cases, it is a conservative approach, standards, and a slow legislative process that fails to keep pace with new technologies. And this isn’t just the case in the Czech Republic, but also in Slovakia. Our legislation isn’t entirely open to innovation, and we sometimes encounter investor concerns, which is understandable because this is something new.