Stable Equi­lib­rium

In our research approach of the segmented mobile we want to give an idea of the wide spectrum of opportunities of post-tensioned slender concrete structures. The segmented system derives from the modularization for transport of the prefab elements and an efficient and accurate assembly on site. 
The chosen material is DUCON®, which stands for DUctile CONcrete. It is a composite material of a high-performance concrete and a micro reinforcement of steel wire meshes stapled layer wise over the entire cross section. In between the mesh reinforcement, hulls for post-tensioning cables are cast in the concrete. These cables are manufactured with screw-threads on both ends that allow setting the post-tensioning by tightening the screw nuts. 
The mobile shows the possibility to design structures from an initially heavy material that appears to be light and floating. The developed system allows a quick and accurate assembly on site; the only tool required will be an open end spanner to set the post-tensioning and to fix the suspension cables.

picture "Mobile 01":  Stefanie Pretnar
Team: Prof. Manfred Grohmann, Philipp Eisenbach, Magdalena Hellmann, Moritz Rumpf
with generous support from: DUCON Europe GmbH, ARNOLD AG, Carl Stahl GmbH, AMPA – Amtliche Materialprüfanstalt 

Eisenbach P., Grohmann M.: Structural Implementation of Slender Concrete Shells with Prefabricated Elements; Journal of the International Association for Shell and Spatial Structures (J. IASS), Vol. 58 (2017) No. 1 March n. 191, ISSN: 1028-365X; S. Adriaenssens and P. Block (Guest Editors) special issue “New directions for shell structures"; p. 51-64
Eisenbach, P.: Processing of Slender Concrete Shells - Fabrication and Installation; 2017
Grohmann M., Eisenbach P., Rumpf M.; Hellmann, M.: Stable Equilibrium – on-site mounting technique of lightweight concrete structures; Proceedings of the IASS2015 Annual International Symposium on Future Visions, Amsterdam; August 2015