Casting concrete: Geiger Group's collaboration with Nowlab
Problems during the restoration of buildings.
The Geiger Group, founded in 1923, specializes in development, design and construction. One of their projects is the restoration of an old brewery in Kempten, in southern Germany. It was necessary to replace five large stone window panes and at the same time preserve the original appearance of the building.
When replacing the stone shafts, one of two common solutions could be applied. The first, traditional solution, is the use of stone cutting services. However, stone carving services are expensive and the manufacturing process is time-consuming. Another solution is to pour concrete into a resin-coated foam mold. Due to the depth of the pattern, a suitable foam mold could not be made, and the production of the shaft from several parts takes a long time and the costs are high. Another disadvantage of this method is toxicity and a large amount of waste.
"It is very expensive to make complex geometric shapes from concrete on site. It's mostly manual work, people make separate wooden molds, which we use once and then throw away." Jerg Petri, Director of Innovation, NOWlab@BigRep
The Geiger group had a short deadline to complete the work and turned to the research and innovation center NOWlab, which works as part of the 3D printer manufacturing company BigRep, for help.
Process – “We use less concrete because we achieve structural stability through complex geometry. In pouring concrete into 3D printed molds, we see the possibility for architects to take direct control, from design to implementation on the construction site itself." Jerg Petri, Director of Innovation, NOWlab@BigRep
After considering the possibilities, NOWlab and Geiger decided to collaborate on the creation of windows, and established steps in their production.
Geiger provided CAD files that contained detailed specifications for the window panes. NOWlab used these files to create a digital mold to make the formwork. They created G-code files using SIMPLIFY3D software for 3D printers, printed the formwork on the BigRep ONE, using its volume to print the entire model at once.
The printed formwork, made from BigRep's biodegradable PLA, was sent to a fabricator to cast the concrete parts. The assembly of the windows itself was done on the construction site itself, before the successful installation. In this case, the client already had the CAD files, but otherwise NOWlab could have created them, starting from scratch or from a 3D scan of the template.
"You can rely on 3D printing technology to create a true life-size copy of your design." Then you can apply it in the real world.” Jerg Petri, Director of Innovation, NOWlab@BigRep
At Geiger Group, they estimate that by making window panes with 3D printing in NOWlab,
the costs were reduced by up to 50% compared to using the services of a stone cutter, and
they saved 45% in time compared to casting in a foam mold. Also,
less labor force was engaged . Combined with a high-quality finish, this was the ideal 3D printing solution for the Geiger Group.
Products for the future
It is likely that over time the Geiger Group and other companies will adopt this method in their work. However, restoration is only one of the fields of application of this technique. NOWlab is developing processes for casting concrete into 3D printed molds for the future. Both for the production of facades and structural load-bearing elements. A patent for the production of 3D printed formwork is also in the development phase.
The advantages of 3D printing: faster production, saving resources, care for the environment, also apply to these processes. However, with new products, 3D printing also opens up new possibilities in design. We can expect new surface textures, external shapes and structural features to emerge in design, freed from current constraints. In this way, concrete casting based on 3D printing provides a vision of a different future in architecture and construction – both in restoration projects, such as the one carried out by the Geiger Group, and in innovation in architecture. BigRep ONE is here to enable ideas to become reality.
"You can rely on 3D printing technology to create a true life-size copy of your design." Then you can apply it in the real world.” Jerg Petri, Director of Innovation, NOWlab@BigRep
At Geiger Group, they estimate that by making window panes with 3D printing in NOWlab, the costs were reduced by up to 50% compared to using the services of a stone cutter, and they saved 45% in time compared to casting in a foam mold. Also, less labor force was engaged . Combined with a high-quality finish, this was the ideal 3D printing solution for the Geiger Group.