Elimination of swelling stresses from measurements of the equilibrium constant in silica

The reaction of water with silica is described by the equilibrium constant k. This property depends on temperature and is affected by stresses. The experimental determination of k is in most cases carried out in presence of swelling stresses. Knowledge of the reaction volume $\mathrm{\Delta }$$\bar{V}$ allows an elimination of the swelling stresses and the determination of an equilibrium constant for the case of a stress-free material. An analytical expression of k${}_0$ as a function of temperature, k${}_0$=f(T), will be suggested.