Effects of Nano-Al2O3, Nano-MgO and Nano-Fe2O3 on the Properties of Cement-Based 3D Printing (2025-07)¶

Nanomaterials provide a new way to control the properties of cement-based composites due to their unique microstructural effects and surface properties. Nano-Al2O3 (NA), Nano-MgO (NM) and Nano-Fe2O3 (NF) are commonly used to modify concrete composites. In this study, these three functional nanomaterials are selected to systematically study their effects on the fresh properties, printing properties and hardening properties of cement-based materials. The research shows that adding an appropriate amount of NA, NM, and NF nanomaterials can reduce the flowability, improve the printability and enhance the physical and mechanical properties of the printing material. Among them, the physical and mechanical properties of the printing mortar with 3∼4 wt% NA and 4 wt% NF are the best, but the compressive strength of the printed specimens with 2 wt% NM reach the highest values. The microscopic mechanism indicates that the 4 wt% NA sample has the fewest pores due to NA accelerating cement hydration. There are more harmful pores in 4 wt % NM specimens because NM exhibits expansive properties. NF can make the cement matrix relatively dense by refining the crystal size of Ca(OH)2 crystal. The research results can provide new ideas and methods for the nanomaterials modification of cement-based 3D printing materials.