Hydrating tricalcium and dicalcium silicate mixtures were studied using time-resolved quasielastic neutron scattering. Application of a hydration model allowed the extraction of several parameters describing the hydration mechanics. The hydration rate during the nucleation and growth period, diffusivity during the diffusion limited regime, and the maximum amount of product able to be formed were not related linearly to the mixture combinations. Addition of dicalcium silicate at approximately 20 wt. % caused a sharp alteration to these parameters, including reduced hydration rate and reaction layer permeability. These two factors lead to the prediction that more reaction products would be ultimately manufactured during the reactions at this composition.