Figure shows the predicted Ca NMR spectra at the different DoH of C 3 S studied. The here reported Ca NMR spectrum of C 3 S assumes an Ca enriched sample, therefore the resolution of this theoretical Ca NMR spectrum is much higher than of the experimentally measured one with natural abundance. At 43% DoH of C 3 S, the formation of C-S-H results in a separate peak at 33 ppm, while the formation of CH converts the right C 3 S shoulder into a separate peak. As the hydration reaction continues (83% DoH, Figure ), the decrease in the C 3 S content is seen as a decrease in the main C 3 .S peak at 93 ppm and its 150-120 ppm shoulder . Simultaneously, the C-S-H and CH peaks rise proportionally. The 70 ppm (CH) and 34 ppm (C-S-H) peaks become dominant. At 463 h (99% DoH, Figure ), the C 3 S related resonances between 90 and 150 ppm almost completely disappear, and the C-S-H and CH peaks are the only remaining. Nevertheless, the spacing between the main C 3 S, CH and C-S-H lines in the Ca NMR spectra suggest that, in real experiments, deconvolution should be feasible to implement provided that the line shape is properly accounted for, enabling computation of the DoH of C 3 S even at later ages, along with a precise determination of CH content. As these parameters can also be quantitatively accessed by independent techniques (XRD and XRD/TGA, respectively), this could provide a pathway for the validation of results.