Experimental Study and Numerical Modeling of the Solidification Capacity of Chloride Ions in Alkali-Activated Slag Cement Exposed to Sodium Chloride

The effects of chloride concentration and alkali activator on the phase alteration and chloride solidification capacity of alkali-activated slag (AAS) cement exposed to sodium chloride were investigated by multiple experimental techniques and thermodynamic modeling. In the meantime, a novel model considering the binder composition and solution chemistry was developed for the first time to predict the chloride solidification capacity of AAS. The experimental results were presented, discussed, and used to validate the model. A good agreement was found in the comparisons, showing R2 ≥ 0.93. The model was then implemented to study the effect of slag chemistry, and it revealed that increasing CaO content in slag increased the physical adsorption capacity, while the slag with high contents of Al2O3 and MgO exhibited larger chemical binding capacity.