Durability of a new type of cement-based composite grouting material under effects of chemical corrosion

Corrosion resistance and durability are important performance features for grouting materials in underground engineering. The grouts based on ordinary Portland cement are difficult to solve water inrush disasters. To solve these problems, a new type of sulphoaluminate-cement-based Composite Grouting Material (CGM) has been developed. In this research, the chemical corrosion mechanism was analyzed, and the durability and anti-corrosion performance of CGM were studied under different concentrations of sulfate and chloride ions, steel slag contents and water/CGM (W/CGM) ratios. The flexural strength, compressive strength and corrosion resistance coefficient of CGM were measured in dependence of the days. Scanning electron microscopy (SEM) analysis was carried out to determine the anti-corrosion characteristic of CGM. The results showed that the corrosion resistance coefficients of CGM are generally larger than 1.0 under different sulfate and chloride ion concentrations. Steel slag prevents sulfate ions from penetrating the hardened stone body, and the anti-corrosion performance of CGM was relatively low at high W/CGM ratios.