Enhancing Soil Dynamic Properties with Magnesia Cement: Exploring Mechanical Behavior and Microstructural Evolution in Waste Soil Stabilization under Small Strain

In geotechnical engineering, the small-strain shear modulus and its attenuation characteristics play a vital role in understanding and predicting the vibration behavior of soils, which is essential for evaluating the performance of various engineering constructions. This research explores the small-strain dynamic properties of magnesium oxysulfate cement soil (MOCS) using resonant column tests and advanced microstructural analyses [scanning electron microscopy (SEM), X-ray diffraction (XRD), mercury intrusion porosimetry (MIP)]. Results indicate that the dynamic shear modulus of MOCS increases with both confining pressure and curing age, whereas its damping ratio displays an inverse relationship with these parameters. The maximum dynamic shear modulus occurs at an MgO - to - MgSO 4 ratio of 8 ∶ 1 . The Hardin-Drnevich model was used to normalize dynamic shear modulus and damping ratio with shear strain, and its validity was confirmed by regression analysis. Microstructural examinations reveal that magnesium oxysulfate cement enhances hydration product formation, reducing porosity and improving material integrity. These findings highlight magnesium oxysulfate cement’s potential to optimize MOCS formulations, advancing sustainable construction practices. This research contributes valuable insights into optimizing MOCS formulations, thereby advancing sustainable construction practices and offering significant implications for practical geotechnical engineering applications.