Moudrakovski et al. carried out Ca NMR spectroscopy on hydrated triclinic C 3 S. Since the authors studied the Ca NMR spectra under natural abundance of Ca the spectrum is very broad and noisy. However, the CH peak is clearly seen around 70 ppm. The absence of the left shoulder from the CH peak suggests that C 3 S fully reacted by the time of measurement. The spectrum has a wide range of broad signals from 20 to 70 ppm, and therefore the C-S-H peak cannot be distinguished from it. However, these theoretical study on triclinic C 3 S hydration (Figure ) shows that Ca NMR could be a useful tool in monitoring the cement reaction, provided that a better signal-to-noise ratio can be achieved.