In this study, the effects of bentonite, diatomite, and metakaolin on the rheological behavior of 3D printed magnesium potassium phosphate cement composites (3D printed MKPCs) were investigated through characterization of the material properties, including yield stress, plastic viscosity, thixotropy, and creep. The thixotropy was studied by assessing the hysteresis area and thixotropic parameters under dynamic shear tests. The structural stability was evaluated by assessing the creep recovery, modulus of the fresh cement pastes, and deformation rate of the printed specimens. The results showed that diatomite played a key role in enhancing the thixotropy of the 3D printed MKPCs. Bentonite was found to significantly enhance the static yield stress, creep resistance, and shape stability owing to its high water absorption in the 3D printed MKPCs. Isothermal calorimetry testing showed that all additives accelerated the hydration reaction, which was confirmed by the increased compressive strength. Finally, a schematic representation of the yield stress evolution with time was proposed, revealing the beneficial effects of three additives in MKPCs during different stages of 3D printing.

在本研究中，通过表征材料特性，包括屈服应力、塑性粘度、触变性和蠕变，研究了膨润土、硅藻土和偏高岭土对 3D 打印磷酸镁钾水泥复合材料（3D 打印 MKPC）流变行为的影响。 . 通过评估动态剪切试验下的滞后面积和触变参数来研究触变性。通过评估蠕变恢复、新水泥浆的模量和印刷试样的变形率来评估结构稳定性。结果表明，硅藻土在增强 3D 打印 MKPC 的触变性方面发挥了关键作用。发现膨润土由于其在 3D 打印 MKPC 中的高吸水性而显着提高了静态屈服应力、抗蠕变性和形状稳定性。等温量热法测试表明，所有添加剂都加速了水合反应，这通过增加的抗压强度得到证实。最后，提出了屈服应力随时间演变的示意图，揭示了 MKPC 中三种添加剂在 3D 打印的不同阶段的有益作用。