Study on the degradation mechanism of CSCGM grout stones under salt ion erosion

As a new type of cement–water glass composite grouting material independently developed, CSCGM is composed of A and B double liquids. Liquid A is modified by adding metal silicon powder, xanthan gum, and polyacrylamide based on cement slurry, and liquid B is water glass solution. Compared with traditional grouting materials, it has more advantages with mechanical properties and corrosion resistance potential and can better adapt to the engineering needs in a complex erosion environment. In order to explore the ability of the material to resist the damage of the external environment during the service stage, this study systematically explored the strength evolution of CSCGM stone bodies under different salt ions (Cl− and SO42−), different concentrations (3, 10, and 20 g/l), and different erosion conditions by indoor accelerated erosion tests and clarified the degree of deterioration of various salt ions on the stone body as well as the correlation mechanism between the salt ion concentration, erosion age, and deterioration process. The Marquardt algorithm was used to construct the ion type–age and concentration–age function models, and the relationship between the salt ion concentration and erosion rate and the difference in degradation were accurately quantified. Combined with the macroscopic characterization analysis method, the evolution characteristics of the appearance structure of the stone body after erosion were observed, and the differences in the chemical composition were analyzed. The combination of macro- and micro-level analyses revealed that different salt ions led to the deterioration of the CSCGM stone body.