An analysis of the deterioration mechanism of a grouting stone under the ion erosion

Research on the degradation mechanism of cement-water glass grouting stones (C-S stones) in an environment of ion erosion is lacking. The unconfined compressive strength test is conducted to analyze the change law of macro-mechanical properties of the C-S calculus body under different age conditions after the erosion of three different concentrations of sulfate. A combination of SEM, EDS and XRD is used to observe the mesostructure and chemical composition changes of the stone body, and reveal the mechanism of ion erosion damage of the grouting stone body. The results show that within 28 days of erosion, different concentrations of ionic solutions has no significant effect on the growth of stone strength. From 28 to 90 days of erosion, the growth of stone strength in high concentration solution is significantly degraded, and when the concentration of \rm SO_4^2- solution is 20 g/L, the 90 d intensity value of the stone body is only 2.43% of the 28 d intensity value. The chemical composition of the stone body changes under the influence of ion erosion, which destroys the stability of the internal structure and greatly reduces the compressive strength. For the C-S stone body, the main damage of ion erosion is \rm SO_4^2- erosion, and the degree of erosion damage is \rm SO_4^2- > \rm SO_4^2- & \rmCl^- mixed solution > \rmCl^- > clear water under the same ion concentration solution. The research results may provide a reference for the prevention and control of the grouting stone body deterioration under the ion-eroded environmental conditions such as seawater inversion and groundwater pollution.