Aging Of Clay Based Materials

One of the general symptoms of ageing is a volume change due to the moisture exposure, known as irreversible moisture expansion (IME). It is assumed IME of fired clay based materials is governed by the presence of inner surface and interlamellar OH-groups, present in clay minerals and assumed to be also abundant in amorphous intergranular phases. IME was measured on a series of clay based ceramics bodies with a variable content of raw minerals under two different hydrothermal conditions. IR spectroscopy was used to correlate IME with the increasing amount of inner and interlamellar hydroxyl groups.