【摘要】 本文采用自主研发的混搅挤功能一体化建筑3D打印设备,实现了轻烧氧化镁基磷酸镁水泥材料的3D打印,探究了不同掺量偏高岭土(MK)对3D打印轻烧氧化镁基磷酸镁水泥性能的影响规律,并结合XRD与SEM试验进一步分析MK掺量对3D打印轻烧氧化镁基磷酸镁水泥水化产物及晶体形貌的影响。结果表明:3D打印轻烧氧化镁基磷酸镁水泥的凝结时间与力学性能均随着MK掺量的增加呈先上升后下降的趋势;当MK掺量为胶凝材料质量的4%～6%时,MK的加入有效改善了轻烧氧化镁基磷酸镁水泥浆体的打印性能,此时的轻烧氧化镁基磷酸镁水泥具有良好的挤出性能、建造性能与力学性能,能够满足3D打印应用要求;MK的加入不会改变轻烧氧化镁基磷酸镁水泥水化产物晶体的组成,但会产生大量无定形的非晶体水化产物,进一步填充水化产物与颗粒间的空隙,改善结构密实程度。更多还原

【Abstract】 In this paper, the 3D printing light burned magnesia-based magnesium phosphate cement material was realized by using the self-developed integrated building 3D printing equipment with mixed stirring and extrusion function. The effect of different metakaolin(MK) content on the properties of 3D printing light burned magnesia-based magnesium phosphate cement was investigated, and combined with XRD and SEM test to further analyze the influence of MK content on the hydration products and crystal appearance of light burnt magnesia-based magnesium phosphate cement. The results show that the setting time and mechanical properties of 3D printing light burnt magnesia-based magnesium phosphate cement increase first and then decrease with the increase of MK content. When MK replaces 4% to 6% of the total mass of magnesia and potassium dihydrogen phosphate, the addition of MK effectively improves the printing performance of light burnt magnesia-based magnesium phosphate cement paste. At this time, the light burned magnesia-based magnesium phosphate cement has good extrusion performance, construction performance and mechanical properties, which can meet the application requirements of 3D printing. The addition of MK does not change the crystal composition of the hydration products of light burnt magnesia-based magnesium phosphate cement, but produces a large number of amorphous amorphous hydration products, which can further fill the gap between hydration products and particles and improve the compactness of structure.更多还原