Study on Compaction and Unconfined Compressive Strength Characteristics of Magnesium Carbonate Mixed Soils

As the global urgency to stem global warming increases, the need to implement negative emissions technologies grows with it. This study takes into consideration one such proposed desalination brine conversion technology, capable of making use of its product magnesium oxide (MgO) to mineralize CO2 and produce magnesium carbonate (MgCO3). Recognizing the necessity to find feasible applications for the output non-plastic MgCO3, this paper outlines the study done to evaluate the performance of MgCO3 as a geomaterial by taking into account the material properties and unconfined compressive strength (qu) characteristics of a clayey soil mixed with 0–40 wt.% MgCO3. It was found that further addition of MgCO3 progressively reduced maximum dry density and increased plastic and liquid limits and optimum water content. It was also noted that the qu of soil mixtures with 10–30 wt.% MgCO3 were much greater than that of pure soil (i.e., 0 wt.% case). The probable reasons were attributed to the suction effect being lower the pure soil due to the greater than optimum water content used, and the effect instead being higher in mixtures due to increase in finer particles.