P. Theoulakis

Detection of water deposits and movement in porous materials by infrared imaging

Since a large amount of damage in porous materials arises as a direct or indirect consequence of moisture (static and dynamic phenomena), detection and monitoring of moisture in porous materials is important, in an attempt to determine the actual damage, as well as the deterioration rate. The most common methodology to assess the moisture content in porous materials is to collect representative samples from the sites investigated and then weigh them before and after drying. In this research, infrared thermography, an indirect moisture assessment technique, was used in the investigation of various porous stones in the laboratory during capillary rise tests. Supplementary investigation of the stones in terms of their microstructure (mercury intrusion porosimetry) and isothermic behaviour (water sorption) was also performed. Finally, an in field diagnostic survey on historic structures was carried out. The results of this study indicate that infrared imaging provides significant information in the study of moisture in porous materials.

Thermography as an evaluation tool for studying the movement of water through various porous materials: capillary rise and evaporation

In this work, infrared thermography is used for detecting the movement of water - moisture in various porous materials in the laboratory, with the intention of validating the examination of real scale material systems in situ. Different materials have been subjected to capillary rise tests and to cycles of evaporation with water under controlled environmental conditions (Relative Humidity and Temperature). Material samples of a reference porous stone, of three basic categories of repair mortars, of consolidated porous stones and of simulating prototype porous materials were examined in lab. Furthermore, systems like historic masonries, were examined in situ, more specifically the Venetian Fortification in Heraklion, Crete and the Medieval Fortifications in Rhodes, undergoing severe alveolation in the aggressive marine atmosphere of the Aegean. Infrared thermography has been shown to be an effective technique for verifying relations between moisture and environmental conditions. Hence, infrared thermography can be used as an evaluation tool for studying the movement of water through porous materials - water absorption and evaporation.

Stability And Materials WeatheringConditions At The Symonos Petra MonasteryOf Mount Athos, Greece. PreliminaryApproach

The Monastery of Symonos Petra, located in Athos mountain (Greece) was built, the first, around 1257 AC by the Blessed Symon, burnt down in 1891 AC and partially rebuilt. Today, 100 years after its burning down, national interest is attracted on restoration and conservation of that valuable piece of Byzantine cultural heritage. In the present work stability and materials weathering conditions are under study. Materials characterization analysis, as well as a first macroscopic and microscopic estimation of weathering problems were performed. Samples of mortars, as the critical factor of the masonry strength, were studied, regarding their origin and resistance to weathering. The present study concerns the slope stability conditions of the rockmass where the monastery is built as well. It is a preliminary investigation, thus no definitive results can be formulated at this moment.