Mechanical characteristic and microstructure of salt-rich cement soil

To study the influence of the three soluble salt ions of Mg 2+ , Cl − , and SO4 2− on the strength of salt-rich cement soil, an unconfined compression test was conducted on cement soil with different curing times to study the effect of the content of soluble salt ions on the strength of cement soil. X-ray diffraction and environmental scanning electron microscopy were used to study the influence of soluble salt ions on the microstructure and chemical composition of salt-rich cement soil and to reveal the mechanism of interaction between soluble salt ions and cement soil from macro and micro perspectives. The results show that the Mg 2+ , Cl − , and SO 4 2− soluble salt ions have distinct adverse effects on the strength of cement soil samples. Moreover, with the increase in the content of soluble salt ions, the adverse effects become more apparent. The main reason for this phenomenon is that the high content of soluble salt ions consumes C–S–H and C–A–H gels and generates M–S–H, M–A–H, and a large number of crystals. M–S–H and M–A–H dispersed in C–S–H and C–A–H gels can reduce the cementing force of cement soil and the strength of salt-rich cement soil.