Effects in Monitoring of the Thermal Moisture Regime of Cultural Objects Located in Different Climate Conditions

Abstract

Historical monuments are most often built from materials (plaster, walls, rocks, etc.), which have a porous structure. The porous structure is characterized by a set of parameters that control its response to environment. In such structures, depending on the environmental conditions, we encounter with processes like vapor diffusion, adsorption, pore surface diffusion, capillary transport, etc. The processes are accompanied with the transport of heat energy and moisture. When monitoring of thermal - moisture regime of such structures we can find a wide range of effects such as wetting, drying, freezing and thawing. We have monitored several cultural objects localized in different environments, namely the Duomo Cathedral in Florence, the tower of St. Martin in Bratislava and pillar of the St. James Church in Levoča. Building components of the mentioned objects are of different nature such as masonry composed of bricks and plaster, Gioia marble and sandstone. Moisture sensors were used to monitor the thermal – moisture regime based on the hot-ball method for measuring thermal conductivity. The thermal conductivity is a function of the pore content. In the pores, depending on the thermodynamic conditions, air, vapor, water or ice can be found. Collected data are correlated with meteorological conditions.