The layer-by-layer stacking process of 3D Printing Construction Technology (3DPCT) inevitably leads to weak bonding areas between the interlayer interfaces and the interstrip interfaces, which affect the mechanical properties of the printed structure. The effects of different carbonation time of recycled sand on the mechanical properties and interfacial bonding performance of 3D printed cement-based material with a 100 % replacement rate of carbonated recycled sand (3DPCRS) were explored. Although, the carbonation time of recycled sand affected the mechanical anisotropy of the printed specimens, the carbonation treatment of recycled sand cannot eliminate the mechanical anisotropy of 3D printed specimens. With the extension of the carbonation time of recycled sand, the interfacial bonding performance was gradually improved. At 28 days, the interlayer shear strength and interstrip shear strength of T7 group increased by 21.5 % and 18.7 %, respectively. After the carbonation of recycled sand, the indentation modulus of the interlayer interface was increased with the decrease of interface width and porosity, which improved the pore structure and the mechanical properties of the printed specimens.

中文翻译：

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碳酸盐再生砂对 3D 打印水泥基材料界面粘结性能的影响


3D 打印结构技术 （3DPCT） 的逐层堆叠过程不可避免地导致层间界面和条间界面之间的粘合区域薄弱，从而影响打印结构的机械性能。探讨了不同碳化时间对碳酸盐再生砂替代率 100 % 的 3D 打印水泥基材料的力学性能和界面粘合性能的影响 （3DPCRS）。虽然再生砂的碳化时间影响了打印样本的力学各向异性，但再生砂的碳化处理并不能消除 3D 打印样本的机械各向异性。随着再生砂碳化时间的延长，界面结合性能逐渐提高。28 d时，T7组的层间剪切强度和条间剪切强度分别提高了21.5 %和18.7 %。再生砂碳化后，层间界面的压痕模量随着界面宽度和孔隙率的减小而增加，改善了打印样品的孔隙结构和力学性能。