Base Performances of Cement-Stabilized Magnesium Slag-Aeolian Sand Mixture

Many problems are encountered in the disposal of abundant magnesium slags, remarkable ecological environmental damages by stacking and landfill of magnesium slag, poor properties of soil-rock materials, and high pavement cost in Yulin City, China. This study focused on the combined use of feasibility of magnesium slag-Aeolian sand in pavement base to address the problems above. The physical and chemical properties of magnesium slag and Aeolian sand were obtained through tests on the basic properties of raw materials. Different mixing ratios of magnesium slag and Aeolian sand and cement content were designed. Moreover, a comparative study on the compaction characteristics and water stability, as well as unconfined compressive strength, splitting strength, and compressive modulus of resilience of five groups of cement-stabilized magnesium slag-Aeolian sand mixtures in different periods, was conducted through a series of systematic laboratory tests. The impact degrees of different factors on compressive strength were calculated by the grey relational analysis method. Finally, the test section was paved by combining laboratory test results. Research results demonstrate that the active matter content is high, and the crushing value of magnesium slag is also high. The optimal water content of the mixture increases with the magnesium slag content, while the maximum dry density decreases. The mixture's unconfined compressive strength, splitting strength, and compressive modulus of resilience in different curing periods all increased with the magnesium slag and cement contents. Moreover, magnesium slag content has minimal influence on splitting strength compared with unconfined compressive strength. Among all factors, cement content provides the most influence on the compressive strength, followed by water content, magnesium slag content, and curing period successively. The 7 d compressive strength of mixtures with different mixing ratios meets the strength requirements of the base and subbase of different highway grades, and all mixtures show good water stability. The test road also achieves good performance. These findings prove that using cement-stabilized magnesium slag- Aeolian sand mixture as the pavement base and subbase materials is feasible. The magnesium slag content should be higher than 45% under 5% cement content to meet the strength requirements base. This study can provide references to the applications of magnesium slag and Aeolian sand in semi-rigid base materials.