Effect of spiral blade geometry on 3D-printed concrete rheological properties and extrudability using discrete element modeling

Sizes and shapes of spiral blades have a great influence on 3D printable concrete construction. This study is presented to answer two research questions: How does spiral blade geometry affect rheological properties of 3D printing mixtures? What are effects of the rheological properties of 3D printing mixture on final extrudability? The discrete element model formed by particles bonded with liquid bridges is used to analyze the influence of 3D printer blade size, shape, and rotation speed on the extrudability of cement-based materials. It is demonstrated that effects of spiral blade geometry on rheological properties and resulting extrudability of 3D printing mixtures are considerable. The research results could be good references about geometry of spiral blades for 3D concrete printing industry. However, the microscopic time-varying constitutive model of particle bonding has not been generated in this paper. It might be one of the future research directions.