In saline-alkali and coastal areas, cement soil faces various threats from salt erosion, and these environmental conditions can significantly impact the mechanical properties of cement soil. To counter external erosion, the addition of graphene oxide (GO) nanomaterials to cement soil is considered an effective solution. This study systematically investigates the strength variations of GO cement soil after erosion in different concentrations of NaCl solution (0 g/L, 4.5 g/L, 18 g/L, 30 g/L), Na2SO4 (0 g/L, 4.5 g/L, 18 g/L, 30 g/L), and a composite salt solution of both (0 g/L, 4.5 g/L, 18 g/L, 30 g/L) at different times (7d, 14d, 30d, 60d) through salt immersion tests, unconfined compressive strength tests, and SEM scanning electron microscope tests. Simultaneously, the study analyzes the mass change rate, stress-strain curves, peak stress of unconfined compressive strength, and modulus of elasticity changes in cement soil samples after erosion. The internal erosion mechanism of cement soil samples is explored at the microscopic level. When the GO cement soil was eroded in different concentrations of NaCl solution for 14 days, a consistent trend of mass decrease was observed. However, after 7, 30, and 60 days of erosion in various concentrations of NaCl solution, the mass showed an increasing trend. When immersed in pure water for 7d, 14d, 30d, and 60d, as well as in a 4.5 g/L NaCl solution for 7d and 14d erosion, the peak stress of GO cement soil samples shows an increasing trend, while it decreases under other conditions, especially significantly in Na2SO4 solution. Simultaneously, Na2SO4 has the greatest impact on the modulus of elasticity of cement soil. SEM test results reveal that due to nucleation effects, GO promotes the generation of hydration product C-S-H, enhancing the resistance of cement soil samples to external erosion. Furthermore, it is observed that under the influence of SO42-, C-S-H undergoes decalcification to generate AFt, while the impact of Cl- on C-S-H is relatively small.

In coastal and saline-alkali regions, cement soil materials face significant challenges from salt erosion and both dynamic and static loads, threatening their structural stability. To enhance the mechanical properties of cement soil, this study explores the incorporation of graphene oxide (GO). We subjected GO cement soil specimens to various concentrations of a composite salt solution (with a NaCl to Na2SO4 mass ratio of 1:1) in erosion experiments lasting 7 and 30 days. The specimens were analyzed through unconfined compressive strength tests, split Hopkinson pressure bar (SHPB) tests, and scanning electron microscopy (SEM) to examine changes in stressstrain curves, peak stress, and energy dissipation. The results indicate that the dynamic and static peak stresses, energy absorption, and energy absorption efficiency of the GO cement soil specimens are inversely related to the concentration of the mixed salt solution. Notably, in a 4.5 g/L erosion environment after 7 days, an increasing trend was observed in static peak stress, energy absorption, and energy absorption efficiency. Additionally, when the salt concentration was fixed, these properties showed a positive correlation with impact gas pressure. SEM analysis revealed that the nucleation effect of GO and its strong bonding with the cement matrix significantly improved the microstructure of the specimens by reducing pores and defects, thus enhancing density and overall performance. Furthermore, in an 18 g/L erosion environment, a notable presence of ettringite (AFt) was identified in the GO cement soil specimens.