Self-dynamics of water molecules has been studied in hydrated tricalcium silicate as functions of temperature, aging, and in the presence of an additive. A dynamical model taking into account the existence of "immobile water" and "glassy water" has been used to analyze quasielastic neutron spectrometer spectra. We deduced the fraction of the immobile water (p), the stretch exponent (beta), and the average relaxation time (tau) of the glassy water. A quantitative picture for an aspect of the kinetics of the curing process and the structural relaxation parameters of the glassy water have been established.