Effect of shaping plate apparatus on mechanical properties of 3D printed cement-based materials: Experimental and numerical studies

Precisely controlling the shape of the printed-layers, eliminating the curved sides and internal stress concentration, and increasing the mechanical properties are essential to guarantee the quality of 3D printed cementbased structures. This work aims at achieving the above-mentioned targets through a specially designed shaping plate apparatus. The pressure (stress) distribution in the printed structure with a shaping plate apparatus (SP-3DPC), and the cross-sectional shape, microstructure and mechanical properties of SP-3DPC were systematically investigated. Results indicate that using the shaping plate apparatus may slightly reduce the printing speed, but it can effectively constrain the free expansion of extrudate, control its cross-sectional geometry, and improve the surface finish quality and mechanical properties of the printed structure. This study provides a theoretical basis and technical guidance for the design and application of the shaping plate apparatus.