  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 cement-based
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.
