Monitoring the hydration of MgO-based cement and its mixtures with Portland cement by 1H NMR relaxometry

The hydration process of MgO-based cement, Portland cement, and several mixtures of them was investigated for 1 month by measuring 1H transverse relaxation times (T2) of the different fractions of water inside pastes by means of the Carr-Purcell-Meiboom-Gill pulse sequence. The obtained T2 distributions were exploited to get information on the kinetics of the hydration process and on the evolution of the porous structure of the calcium silicate hydrate (C-S-H) and magnesium silicate hydrate (M-S-H) binder phases as a function of time. The analysis of solid echo 1H Free Induction Decays was employed to determine the relative amount of hydrogen-containing solid phases present in pastes at the longest hydration time.