Anisotropic properties of additively manufactured concrete elements

Robotic concrete extrusion is a novel additive manufacturing process (three-dimensional concrete printing) and is part of a continuously digitally controlled value chain. According to the state of the art, concrete is considered to be an isotropic material due to the manufacturing process. However, for the additive manufacturing process, the isotropic approach has to be reconsidered due to the layered structure. It can be assumed that due to the layered structure, the material properties vary depending on the deposition direction and the geometry of the layers. The aim of the work was to record the material-technical characteristics of extruded elements manufactured according to standards in comparison with concrete recipes. Process-related influences on the mechanical parameters of additively manufactured concrete elements were examined and evaluated in more detail. Based on the findings obtained, the dimensioning, design and measurement of components can be carried out and thus guidelines for components can be derived. With these derived guidelines, the material utilization and economic efficiency can be improved.