2. General phenomenology of water damage to glass

Generally speaking, after water has penetrated the glass (hydration) and after a very short initial stage marked by predominant interdiffusion (preferential release of lattice-modifying elements, leading to the formation of a hydrated layer), glass dissolution becomes congruent for the major elements (Si, B, Al...) and is dominated by the hydrolysis reaction of the silicate lattice. This is the phase during which the glass dissolves at its initial rateV ₀ ; this phase, measured in pure water, is characteristic of the matrix's intrinsic stability. For SON68 glass, the initial velocity V ₀ at 90°C and neutral pH is 0.32 μm/d (approx. 0.9 g · m ^–2 · j ^–1 ).

This phase, which is short in...