Study on Properties of Magnesium Oxychloride Cement Solidified Soil

Abstract

Due to the poor performance of ordinary Portland cement (OPC) as a solidified soil road and the large pollution in the production process, environment-friendly magnesium oxychloride cement (MOC) was used as the soil curing agent to prepare the solidified soil, exploring the optimal ratio of various raw materials when MOC is used as a curing agent. Analyzing the properties of MOC solidified soil in the application of road subgrade. This paper tests compaction, mechanical properties, and durability of the MOC solidified soil, simulates the development trend of 7 days unconfined compressive strength of MOC solidified soil, and then analyzes the hydration process and strengthens the formation mechanism of MOC in solidified soil. The study found that the addition of MOC as a curing agent to the soil can effectively improve the compaction and mechanical properties of the soil. Matlab simulation found that when the MgO content is 5.5% to 6% and the ratio of raw materials MgO, MgCl2, and H2O is 2.45 : 1 : 14 to 6.3 : 1 : 14, the performance of MOC solidified soil is excellent. Fitting UCS data, it is found that MOC solidified soil has early strength characteristics. The excellent compaction and mechanical properties of MOC solidified soil are due to the formation of a small amount of phase 5 and layered Mg(OH)2 by the hydration of MOC, and the formation of amorphous gel with SiO2 in the soil. This reaction improves soil compaction and reduces internal porosity from a microscopic perspective. The strength loss rate of MOC solidified soil is higher after immersion in water at the initial stage of curing, but it is still better than that of traditional cement-based solidified soil. Poor performance after immersion in water is associated with disruption of the network-like structure. As an environment-friendly soil curing agent, MOC can be used in engineering practice with low environmental humidity.