Study on the synergistic mechanism of mechanical response and microstructural evolution in cement-silt-modified aeolian sand

Aeolian sand typically exhibits high porosity and permeability. Enhancing its mechanical properties is crucial for realizing its resource utilization and advancing low-carbon, environmentally friendly applications. As desertification intensifies globally, the abundant availability of aeolian sand presents significant potential for use in infrastructure construction, provided its properties can be effectively improved. In this study, unconfined compression tests and scanning electron microscopy (SEM) were employed to systematically investigate the effects of cement content, soil-sand ratio, and other factors on the compressive strength of modified aeolian sand. Methods such as grey relational entropy analysis were used to quantitatively evaluate the influence of various factors and rank their correlation degrees, thereby clarifying the synergistic mechanisms among them. The results demonstrate that cement content is a pivotal factor affecting the compressive strength of modified aeolian sand. Furthermore, interactions among factors, including cement and silt, collectively enhance material compactness and improve compressive strength. This synergistic mechanism represents a core strategy for enhancing the mechanical properties of aeolian sand. The study provides a scientific basis for designing and constructing modified aeolian sand materials, promotes the application of low-carbon and eco-friendly building materials, and supports the effective utilization of aeolian sand in high-speed railway subgrade construction. It offers theoretical and practical guidance for constructing high-speed railways in desert regions.