Abstract:
The glaze layer degradation of a set of Portuguese tiles from the XVII to the XVIII
centuries has been researched. Within this study ageing tests were performed
aimed at investigating a method for the simulation of azulejos physical decay.
The ageing due to the presence of NaCl salt and various conditions of drying
temperature and water saturation have been imposed to the set of tiles that
presented different characteristics and defects on their glaze layer. These defects
were caused by previous degradation or production faults. The results showed that
sample characteristics such as the porosity, vapor permeability and drying rate
were decay drivers, but the existence of some particular glaze defects proved to
be the most critical one.
