# On the global hydration kinetics of tricalcium silicate cement Source: [On the global hydration kinetics of tricalcium silicate cement]() Collection index: [llms.txt]() Data updated: 2025-10-24T15:13:41.258Z Authors: Frank Tzschichholz, Helene Zanni Published: 1996-12-11T10:44:43.000Z ## Abstract We reconsider a number of measurements for the overall hydration kinetics of tricalcium silicate pastes having an initial water to cement weight ratio close to 0.5. We find that the time dependent ratio of hydrated and unhydrated silica mole numbers can be well characterized by two power-laws in time, $x/(1-x)\\sim (t/t\_x)^\\psi$. For early times $t \< t\_x$ we find an \`accelerated' hydration ($\\psi = 5/2$) and for later times $t \> t\_x$ a \`deaccelerated' behavior ($\\psi = 1/2$). The crossover time is estimated as $t\_x \\approx 16 hours$. We interpret these results in terms of a global second order rate equation indicating that (a) hydrates catalyse the hydration process for $t\ t\_x$ and (c) the value of the associated second order rate constant is of magnitude 6x10^{-7} - 7x10^{-6} liter mol^{-1} s^{-1}. We argue, by considering the hydration process actually being furnished as a diffusion limited precipitation that the exponents $\\psi = 5/2$ and $\\psi = 1/2$ directly indicate a preferentially \`plate' like hydrate microstructure. This is essentially in agreement with experimental observations of cellular hydrate microstructures for this class of materials. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()