A new hydration kinetics model of composite cementitious materials,part 1: Hydration kinetic model of Portland cement

This work is the first part of an overall research project that aims to model the hydration kinetics of modern composite cementitious materials. The aim of this part is to build a hydration kinetic model to characterize the hydration behavior of cement at all ages. In this paper, the nucleation and growth of CSH and the diffusion of water are described by a modified BNG model and a modified Jander's model. The kinetic parameters are obtained by simulative fitting of the model to the experimental data. The linear functions between the nucleation and growth rates and the W/C ratios are given in this paper. The apparent activation energy of the nucleation rate constant, growth rate constant, and generalized diffusion constant are approximately 36.0, 37.5, and 42.0 kJ/mol, respectively. Finally, the phase compositions of hardened cement paste are calculated according to the kinetic model and the reaction formula of cement.