Optimisation of magnesium oxychloride cement properties by silica glass

The influence of different parameters on magnesium oxychloride cement (MOC) was investigated in this study. The use of experimental design was found to be very beneficial for determining suitable experimental conditions to obtain a better composition of cement. The studied factors used to model and optimise the operating parameters were stirring speed, mixing time, mass ratio of magnesium chloride/magnesium oxide, silica glass powder (SGP) percentage and SGP particle size. The considered responses were compressive strength and setting time. The phase compositions of MOC were evaluated by x-ray diffractograms, the morphological properties were examined by means of scanning electron microscopy and phase decomposition was analysed using differential thermal analysis/thermogravimetric analysis. It was found that the use of SGP can enhance the water resistance of MOC by the formation of forsterite, which can limit the decomposition of phase 5 and prevent the formation of brucite in water.