Experimental Study on the Chloride Ion Concentration of Cement Pastes Prepared with Limestone Powder

To investigate the impact of limestone powder on the chloride ion concentration coefficient of cement pastes, various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and mercury-porosimetry (MIP) were employed in this paper. The findings demonstrate that the creation of Friedel's salt is inversely associated with the addition of limestone powder, that is, Friedel's salt production is lessened by adding more limestone powder, however, the coefficient of chloride ion concentration initially decreased and then increased again, as does the porosity, and most likely the pore size as well. The specific surface area of limestone powder has increased, and the content of Friedel's salt increased first and then decreased. However, the shifting trend of Friedel's salt and chloride ion concentration coefficient is in direct opposition, and the pore structure was therefore significantly enhanced. The results of this study offer robust theoretical backing for the inclusion of limestone powder in concrete and provide a positive assessment of its potential applications.