Both the static and dynmanic corrosion tests of E-glass were used for different conditions - temperature, glasss surface to solution volume ration (S/V), solution flow rate, (F) and F/S ratio. Results obtained for glass fibres were compared with the ones for glass fibres were compared with the ones for glass grains and planar smaples. Evaluation of experiemntla results by kinetic models shows that the change of glass surface should be taken into accoutn in the case of fibre corrosion. The total incongruent process of dissolution could be explained as congruent disssolution of glass accompanied by back precipitation of SiO2 or silicates. In most cases, more than 90% of SiO2 precipitates back. The second possible explanation, i.e. SiO2 network dissolution accompanied by selective leaching of Ca, B and Al, is not very probable.
