Experimental Research on the Workability and Mechanical Properties of Grouting Materials with Nano-Oxides

This work studied the effect of the nano-oxides, such as Nano-Fe₂O₃ (NF), Nano-Al₂O₃ (NA), Nano-MgO (NM), and Nano-SiO₂ (NS), on the workability and mechanical properties of quick-setting grouting materials serviced in the underground environment. The results show that 2.0% NS could remarkably shorten the setting time of the grouting materials by 29.16%, compared to the control one (without nano-oxides), and the final setting time was shortened by 46.51%. The results also show that 2.0% NS could decrease the initial fluidity of the grouting material by 41.09%, compared to the control one, and the 30 min fluidity was decreased by 48.93%. The XRD results show that NF, NM, and NS contribute to a higher quantity of AFt than that NA. Moreover, grouting material doped with NF, NM, and NS produces more needle-like ettringite, leading to a more compact structure.