Long-term Properties of Aeolian Sand-magnesium Oxychloride Cement Composites and Its Engineering Application

In order to prepare a new material with long-term stable performance, low cost, easy construction, and ecological environmental protection, the influence of aeolian sand on the compressive and flexural strength as well as micro morphology and phase composition of magnesium oxychloride cement (MOC) was studied. The experimental results indicate that, with the increase of content of doping sand, the compressive strength and flexural strength of MOC decrease significantly. However, when the quality ratio of aeolian sand and light burned magnesia powder is 1:8, the performance meets the actual engineering needs. Namely, the compressive strength of MOC is not less than 18 MPa, and flexural strength is not less than 4 MPa. Meanwhile, within 12 months of age, the compressive strength and flexural strength are stable. There is no obvious change in phase composition, and its main phase is still 5·1·8 phase. Microscopic appearance changes from needle-like to gel-like shape. Based on engineering applications, it is found that when the novel sand-fixing material is used in the field for one year, its macroscopic feature is not damaged, compressive strength and flexural strength are also more stable, phase composition negligibly changes, and micro morphology has also been turned into be gellike shape. These further confirm the long-term stability and weather resistance of MOC doping aeolian sand, providing theoretical and technical support for the widely application of MOC in the field of sand fixation in the future.