Printing time instead of building time, a team of two instead of a construction team, layers of concrete from a giant pump instead of brick on brick. In Germany, the first two residential buildings built with a 3D concrete printer have recently been erected in North Rhine-Westphalia and Bavaria. As a national premiere, construction supplier Peri presented a two-storey single-family house in Beckum, Westphalia. During the inauguration at the end of July, Ina Scharrenbach (CDU), Minister of Construction of North Rhine-Westphalia, underlined a “far-reaching model function”.
The new construction method promises time savings and a “lean construction process”. But is there also potential for flood protection and rapid reconstruction – topics of great concern after the floods?
Significant time savings during construction
With “in-house printing”, a 3D printer uses a huge nozzle to apply concrete and special mortar in centimeter-thick, digitally controlled layers. Beckum’s house was designed by architecture and engineering firm Mense-Korte over a period of several months. But Peri then printed it in just 100 hours. It is still an exhibition project, later a family will move in. The state of North Rhine-Westphalia is financing the project and hopes that the manufacturing process will establish itself on the market and lead to more living space.
Started as a second project, but already inhabited, it is according to Peri the largest printed apartment building in Europe. In the Bavarian Weißenhorn-Wallenhausen (district of Neu-Ulm), it only took about five minutes per square meter of double-walled wall for the three-storey five-storey house, explains Peri. The printer is operated by two people in the process. Recesses, for example for connections and lines, are provided.
Hope for disaster-stricken regions
Architect Waldemar Korte believes 3D printing will be widely used. This means that “the entire residential building, from single-family houses to three-storey office buildings to twelve-part apartment buildings, can be built”. The stability is great. Does he see opportunities for reconstruction measures, like after the July flood? “Certainly,” Korte said. Although it is still a new technology, a time saving of around 30% is already possible compared to other massive construction methods.
Martin Krause of the Institute for Construction Management at TU Dresden has been researching 3D printing of concrete since 2014 – together with construction materials experts and the endowed chair for construction machinery. “Around the world there is a vision and a hope that this will help to quickly rebuild homes in disaster areas.” The scientist sees “very promising application potential for long-term flood protection walls”. However, these massive walls are not suitable for temporary use, i.e. not for movable protective walls, but for long-lasting protection against water masses.
Big changes in the construction industry
And when building a house? “With our full-wall Con-Print-3D process, we can build about three times faster than conventional masonry construction. And we’re five to six times faster than reinforced concrete construction,” says Krause. He sees no difference in stability. Currently, they are also developing printable concrete formulations that have the lowest possible C0.2-Have a footprint. With the Con-Print-3D technology, he cautiously anticipates bringing it to market within five to ten years.
An entire structure like this is to be erected by the end of the year, a kind of modern container building initially for demonstration purposes, the scientist said. The industry is heading for major changes. “We also need the shift towards digitalization and automation of construction processes in order to be efficient on construction sites despite the shortage of skilled labour.
First positive feeling of living
Likewise, the Central Association of the German Construction Industry recently spoke in the Tagesschau about an opportunity to relieve the strained construction industry. IG Bauen-Agrar-Umwelt chairman Robert Feiger told the German Press Agency: “Especially in the affordable housing and social housing sectors, we have a big deficit in Germany, where the printer 3D might be helpful. However, it must be ensured that employees are included in the qualification processes. “Today’s mason should be able to use the computer tomorrow to build the house.”
A Peri spokesperson points out that we have also already printed a first house in the USA and other projects in progress. And how do you live in such a printed house? A few weeks ago, tenant Annika moved into a 60 square meter apartment in Wallenhausen. “It smells a bit stronger of concrete than usual in new homes. And it also echoes a bit, ”explains the 27-year-old. The rental price is “normal”. She loves the grooved look on the exterior walls. “Everything is plastered inside.” The first feeling of living is positive. “It’s something completely new. And I am convinced that the walls are as stable as in a normal house. »