How can 3D printing revolutionize traditional construction methods?

3D printing in the construction industry opens up exciting prospects for the future. The possible applications are diverse, from the rapid creation of prototypes to complete residential buildings. The use of additive manufacturing is becoming increasingly important, as it not only increases efficiency, but also saves resources and enables individual designs. Can this innovative technology revolutionize or even replace conventional construction methods? Florian Greiser and Werner Greiner from EIGNER Betonmanufaktur provide exciting answers to these and other questions in the following interview. We also shed light on the potential and challenges of 3D printing in the construction industry.

Werner, where do you see the potential applications for 3D printing?

Werner Greiner: I see the use of 3D technology as almost unlimited. Be it in the private sector, industry, medicine, architecture or aerospace - this 3D technology is becoming increasingly popular in all areas. It starts with prototypes, buildings, special parts and even small parts. Everything is possible with this technology and, above all, you can use it in your own company.

Why is this 3D printing technology gaining so much importance?

Florian Greiser: In our opinion, the technology is becoming more and more important because you have very short paths from planning to production. This means that you can intervene very quickly if something needs to be changed. Of course, you also become independent of supply chains or suppliers to a certain extent. We also have a very high degree of customization that can be made possible. In our company, we produce to order. This means that when an order comes in, the component is only produced when the customer wants it. The advantage is that we can use 3D printing technology to create free-form shapes, particularly in the concrete sector, that were previously not possible.

For what specific reasons did you get into 3D printing technology and how have your processes improved?

Florian Greiser: We in the construction industry are also really struggling with the shortage of skilled workers. The idea was to use the latest technologies and apply them sensibly in the construction industry, which sometimes lags behind. We actually see the whole thing as a useful addition to the construction industry. In our company, work processes are simplified, for example in the area of integrated formwork or recesses. These were previously always built by hand. Now they can actually be 3D printed. This means that the components are pre-produced in our factory and can then be delivered to the construction site, installed and thus form a permanent bond with the concrete component.

You mentioned the aspect of recess formers earlier. What exactly are recess formers and what advantages and disadvantages do they have?

Werner Greiner: We have specialized in two types of recess formers. Firstly, the classic formwork systems, which are currently still made of wood. The timber is sawn together, nailed, screwed, installed and then removed again. We want to make this technique more practical and solve it using 3D printing. We print these cut-outs and deliver them to the construction site. They are then simply placed on the formwork. They are set in concrete and, as integrated formwork, they remain in the structure and no longer need to be removed. The other variant that we have developed is the so-called hollow formwork. These are thin-walled recess formers with which we create space and displacement in the classic basins so that we have to use less material and the material or concrete is only used where we actually need it. We will use it accordingly. This will save us a lot of concrete and reinforcing steel - in other words, material usage. This also leads to a reduction in CO2 throughout the building. These are the reasons why we want to drive the technology forward in order to make solid construction sensible and sustainable.

What advice would you give to other companies in your sector who would also like to get into 3D printing?

Florian Greiser: You should think about a sensible purpose beforehand. It's not enough to just buy a concrete printer; you should already have a rough idea of what you want to do with it later. For us, the whole thing developed quite organically. The basic idea of no longer producing recess formers from wood, but from concrete, was actually the first idea, which subsequently developed into design projects and hollow core slabs. You should think beforehand about which sector or which direction you want to go in.

Werner Greiner: Ultimately, it's also about the fact that, regardless of which sector I choose, there are different 3D systems and printing techniques that are specifically geared towards the individual sectors. That's why it's important to define the plan, the path I want to take, the technology I need and the possible applications.

As the end consumer, will I notice that the house was made with 3D printed components?

Florian Greiser: That depends entirely on whether you want to see it or not. You can also use the concrete print as a design element if you want to. You can also clad the whole thing, which we think is a shame of course, because the technology can also look quite aesthetically pleasing. In the ceiling area, for example, you could see hollow bodies. But you can also install the hollow bodies so that they are not visible later. The same applies to walls. You can also leave walls with this 3D-printed look or plaster them. But now that 3D printing is becoming more popular, it's nice to look at.

Keyword design. You won the German Architecture Prize for Concrete in 2023. What exactly were you awarded for?

Florian Greiser: Yes, we were awarded for a project that we completed in 2022. The city of Nördlingen wanted to implement a social housing project and we were entrusted with the shell construction work and then actually took the opportunity to use our hollow bodies here on the ceiling or in the ceiling above the underground car park entrance. We did the whole thing in cooperation with Graz University of Technology. The aim was to save a lot of concrete and reinforcing steel. The project is called Concrete Lightweight Ceiling. We installed a total of around 180 hollow bodies in the ceiling. This enabled us to save 40% concrete, around 30% reinforcing steel and a total of around 35% CO2 compared to the originally planned construction method. We were awarded the German Concrete Architecture Prize for this last year. We are very proud that we were able to implement this technology at such an early stage and that it was honored accordingly. It also gives us the opportunity to continue working on and researching the topic in the future. We hope that there will soon be even more ceilings that can be built in a way that conserves resources.

Werner Greiner: The important thing about this ceiling was that it went through a completely normal approval process. We used a well-known and proven ribbed ceiling as a template. This means that the structural analysis could be planned as normal and in this case we did not need approval in individual cases, but were able to build it as normal in order to comply with the regulations we mentioned. That makes us very proud that we have achieved this with so many partners and want to advance solid construction here in the long term.

Will 3D printing replace conventional construction methods?

Werner Greiner: We don't see 3D technology as replacing conventional construction methods. We see it more as a useful addition or as a simplification of construction, because we can simply pre-produce parts thanks to the manufacturing options that we generate here using 3D printing. We can make them more practical for the construction site and there is still a certain and also difficult approval process in the construction sector, which we cannot completely avoid with this topic - not yet. We hope that all of this will also be addressed in this area. We see it more in the direction of saying that we can use this 3D technology to produce great new shapes with old and familiar materials and incorporate them into the design of these house productions.

The interview was conducted by Dr. Tanja Jovanovic, Head of Marketing and Innovation Management, Member of the Management Board, Bayern Innovativ GmbH, Nuremberg.