C₃S hydration in diluted and stirred suspensions: (I) study of the two kinetic steps

The two kinetic steps that occur during C₃S hydration have been investigated further by hydrating C₃S in various solutions: silicate-containing solutions increase the quantity of C-S-H precipitated during the first kinetic step and reduce the second kinetic step. On the other hand, lime solutions increase the second kinetic step and reducethe first one. The influence of the initial composition of the solution and of the water to solid ratio on the relative extent of the two kinetic step intensities has been explained by differences of the kinetic path. The rate of C-S-H precipitation has been calculated from the heat flow. During each kinetic step, the rate of C-S-H precipitation increases and then decreases. Some preliminary hypotheses have been proposed to explain the processes at the origin of these different kinetic regimes.