Water in contact with silica glass surfaces diffuses into the glass, and reacts
with the silica network under hydroxyl generation. Clear evidence has been
reported in the literature for a volume swelling due to the water uptake and
reaction in silica. In the past, the authors showed in a couple of papers the
principle effects of volume swelling by hydroxyl generation on mechanics
and fracture mechanics properties.
From literature data on density as a function of water content a linear
dependence of the volume swelling strain with water concentration was
established. This dependency will be discussed in the present report
including data scatter.