Georg Hansemann (2025): coebro[ceiling]. Strukturleichtbaudecken mittels 3D-gedruckter Schalungselemente aus Beton, 1st reviewer: Stefan Peters, 2nd reviewer: Christoph Gengnagel
Digital fabrication with mineral-based materials is developing rapidly. Additive manufacturing processes such as material extrusion have been tested in various pilot projects and provide the basis for building regulations in 3D printing with concrete. This dissertation implements a practical application for digital fabrication with concrete and conducts accompanying experiments on four real-life construction projects. It develops a system for a novel reinforced-concrete ribbed slab that achieves the required load-bearing capacity through efficient form generation. By using significantly less material, it promotes a resource-efficient use of concrete. Thin-walled concrete formwork produced by material extrusion can thus be used as recess bodies during the on-site concreting of slab elements. Reinforcement is installed using conventional methods, and each component can be completed on site using in-situ concrete construction.
To evaluate the combination of concrete-based 3D printing with traditional manufacturing processes, tests were carried out on load-bearing behavior, adhesive bond strength between printed and normal concrete, fire resistance, sound insulation, and durability. A discussion of these results—together with prototype findings and more than 1,000 square meters of realized slab area—provides insight into the development status of this specific application. Taking sustainability, economic efficiency, and feasibility into account, 3D printing with concrete is being used to develop a new approach to lightweight structural construction for horizontal components such as ceiling and roof structures. It expands and improves traditional production methods in reinforced concrete construction and contributes to a transformation of the construction industry that makes use of the potential of advanced manufacturing technologies, while raising awareness of alternative solution strategies among stakeholders.
