In situ quasi-elastic neutron scattering study of the hydration of tricalcium silicate

We report on the novel application of quasi-elastic neutron spectroscopy to study the reaction mechanism between tricalcium silicate and water. The in situ data taken at a series of fixed temperatures varying from 10 to 40 degrees C show that the amount of free water in the system remains relatively constant for an initial period, ranging from 1 h at 40 degrees C to 16 This is followed by an exponential decrease in the amount of free water that to a diffusion-limited behavior for later times. Fits to an Avrami type behavior allow us to determine an activation energy for the hydration process on the order of 30 kJ/mol.