Multimodal Automated Fabrication with Concrete (2025-02)¶

A substantial portion of concrete in building construction could be saved by producing ribbed concrete ceilings. However, fabricating these ribbed structures is challenging due to the manual effort required for creating the formwork. This paper presents a concept of a modular ribbed ceiling system that integrates topology-optimized design principles with digital manufacturing methods. This modular system comprises a point supported slab-column-connection-module (SCCM) and an inter column-support-strip-module (SSM). An innovative multimodal fabrication technology for producing such ribbed concrete structures is introduced, efficiently combining robotic casting with 3D-concrete printing technologies. Slender, bi-directional orientated ribs are 3D printed onto a robotically pre cast concrete plate with protruding CFRP reinforcement guiding the rib placement. This method allows to produce free form, material-efficient ceilings with high geometric flexibility. Structural tests, including bending, shear and punching shear tests, were conducted to assess the structural performance of these components. The comprehensive process – from design and fabrication to structural testing of multimodal-manufactured components – demonstrates the feasibility of producing material-optimized ribbed CFRP reinforced concrete structures using automated multimodal manufacturing techniques.