Investigation on the solidification effect and mechanism of loess utilizing magnesium oxysulfate cement as a curing agent.

In this study, magnesium oxysulfate cement (MOS) was used as a binder for curing loess. The changes in bulk density, porosity, mineral structure and microstructure of the consolidated loess were systematically studied and verified. The porosity decreased from 40.97 % in pure loess to 28.75 % in 13 % MOS solidified sample. Scanning electron microscopy, energy spectrum analysis and thermogravimetric analysis revealed that the addition of MOS binder resulted in the formation of hydrated products, including Mg(OH)2, MgO·mSiO2·nH2O (M-S-H), and 3Mg(OH)2·MgSO4·8H2O (3·1·8 phase), which effectively filled the voids between the grains and facilitated strong bonding among them. After a curing period of 28 days, the compressive strength of loess stabilized with 13 % MOS exhibited an increase to 7.9 MPa. Moreover, following immersion in water for 24 h, the softening coefficient K remained at 0.66. Furthermore, after undergoing five cycles of freeze-thaw cycling, the rate of change in compressive strength RP was only 6.3 %. All the results indicate that MOS exhibits promising potential as a binder for soil stabilization applications.