After hydration stoppage, the samples were first characterized by 29 Si MAS NMR in order to study the C-(N)-A-S-H gels that formed as primary hydration products. The MAS NMR spectra are presented in Figure , Figure , and Figure . The spectra were normalized with respect to integrated intensities between -50 and -120 ppm. For the decomposition of the spectra measured for the hydrated pastes, the two following hypotheses were used: (i) the dissolution of the slag was considered congruent, meaning that the same line shape was used to model the anhydrous slag contribution for all the spectral decomposition; (ii) a pure Lorentzian line shape was used for all the hydrates contributions except for the Q3 environment in the Na2Si1.7O4.4-activated pastes where a pure Gaussian line shape was used . Moreover, the most hydrated samples were fitted first because they were more resolved. The obtained contributions were then used to fit the spectra of the less hydrated samples. However, it must be recognized that the lower resolution of these spectra increases the incertitude of the decompositions compared to the most hydrated samples and that they are not univocal. All the parameters used to fit the spectra of the hydrated slag samples are reported in