Formwork-free continuous production of adaptive support structures from variable frame elements– Adaptive Concrete Diamond Construction (ACDC) and beyond

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Concrete shells are among the most effective surface-forming load-carrying structures. These material-minimized structures are becoming increasingly attractive in terms of improving environmental sustainability in construction. However, their wide use has been hindered by the standard cast-in-place technology, which to date requires extremely labor-intensive curved formwork and elaborate casting. To resolve this problem, a technology for the automated flow production of flat modules for the subsequent assembly of concrete gridshells was successfully developed in the first phase of the ACDC project and validated through the fabrication of a demonstrator. The project delivered numerous scientific findings in the fields of computer-based design of gridshells and digital fabrication with cement-based materials.In the second phase the project aims to go beyond planar modules; this is also reflected in its new title: ACDC and beyond. The use of double-curved modules and spatial trusses will significantly expand the available geometries for modular shells and push geometric optimization options to a new level. Upcoming research tasks include the parametric modeling of shell structures, the development of algorithms for their segmentation, and their geometric optimization based on the structural analysis performed. Another objective is the development of detachable module connections, which will enable rapid assembly and disassembly of modular structures as well as repair and reuse of individual modules.The transition from planar to double-curved modules leads to considerable technological challenges. For fabrication, an adaptive platform for placing concrete will be built, which is capable of automatically deforming into the required surface geometry. The modules consist of an edge zone and an infill. The edge zone is created by 3D printing using a newly developed strain-hardening cement based composite (SHCC) based on a sustainable binder limestone calcined clay cement (LC3). SHCC ensures high strength and high ductility of the modules for their interaction within the structure as well as high robustness during their transportation and assembly. The curved shapes pose high demands on steering the rheology of the fresh infill concrete and on its time-dependent properties. The infill is reinforced by a freeform robotic textile yarn-laying system based on the requirements resulting from the structural analysis.To establish a direct link between design and manufacturing, an automated data flow system will be created to enable the steering of the adaptive platform, the 3D printer, and the robotic arms based on the specified module geometry. The module fabrication line will be equipped with an in-line control system that will allow the automatic detection of inconsistencies and make the necessary adjustments to the production process. In return, design and layout of the modules will be informed by the production parameters in an iterative process.