In June 2021, the Institute of Structural Design - ITE at Graz University of Technology was commissioned to develop a 167 m² weight-reduced reinforced concrete ceiling over an underground parking garage entrance in Nördlingen, Germany, and to implement it with the companies Eigner Bau and Baumit. The aim was to design a ceiling construction with a significant CO2 reduction that meets both aesthetic requirements and the practical construction requirements on site.
Using 3D printing technology from Baumit, a uniaxially tensioned ceiling with a cantilever was designed at ITE. The corresponding print strategy for 3D printing was developed at the institute and implemented by Eigner Bau. A total of 168 concrete segments were produced and joined together on site to form 48 elongated recess elements with a length of 2.10m to 6.40m.
In order to test the load-bearing capacity and serviceability of the design, a prototype slab section was implemented and subjected to a bending test at the LKI of the TU Graz.
The formwork and reinforcement planning was carried out by Engelsmann Peters and was optimized on the basis of experience from previous projects and the execution was accompanied by the ITE on site. Thanks to the measures taken and the use of a cement-reduced concrete mix for the fresh concrete, the CO2 equivalent was reduced by a total of 47% compared to the original planning.

The project was awarded the Beton 2023 architecture prize.
For more information, visit: www.architekturpreis-beton.de