The Effect of Nano-SiO2, Nano-Al2O3, and Nano-Fe2O3 on the Compressive Strength and Workability of Magnesium Phosphate Cement-Based Mortar

Magnesium phosphate cement (MPC) possesses many excellent engineering properties. The applications of MPC as a repair and quick-construction material have received significant research attention in recent years. The effects of nano-silicon dioxide, nano-aluminum oxide (Al2O3), and nano-iron oxide (Fe2O3) on the compressive strength and the fluidity of the MPC-based mortar are experimentally investigated in this study. The micromorphology and composition of the MPC-based mortar with nanoparticles were captured using scanning electron microscopy and X-ray diffraction, respectively. It was found that the addition of the nanoparticles significantly shortened the setting time of MPC and decreased the fluidity of the MPC-based mortar. The addition of the appropriate amount of nano-Fe2O3 and nano-Al2O3 improved the compressive strength of the MPC-based mortar. The optimal replacement ratios of the nano-Fe2O3 and nano-Al2O3 were 2 % and 4 %, respectively. The reaction product of aluminum phosphate x-hydrate (AlPO4 xH2O) was found in the MPC matrix with the addition of nano-Al2O3, which improved the compressive strength of the MPC-based mortar