INTEGRATED METHODOLOGY FOR MEASURING AND MONITORING SALT DECAY IN THE MEDIEVAL CITY OF RHODES POROUS STONE

Abstract

The main object of this work is to designate the criteria and methodology for an integrated conservation, protection and preservation of historic cities. The results of the in situ Non Destructive Testing measurements are managed by a G.1.S (Geographic Information System), in order to control the environmental factors that accelerate deterioration of the historic building materials. Infrared thermographs, for the assessment of the humidity distribution within the masonries and the degradation _ of the stone texture, are supported by the examination of the microstructural characteristics of the stone and the water percolation within the masonry, regarding soluble salts and humidity measurements. It is demonstrated that these methods can be combined into a reliable appraisal of the critical levels of environmental factors triggering damage to the monument(s). The use of the Digital Image Processing technique, allocates the decay mapping of the historic architectural surfaces. Furthermore, the use of Digital Image Processing combined with ultrasonic measurements to deteriorated materials, provides information for the pattern, the extent and the depth of the decay. The collection and presentation of the data arising from the above measurements and analyses, by using an integrated Geographic Information System, for the Medieval City of Rhodes, allows the effective management of historic complexes from environmental risks; particularly moisture in the case of the Medieval City of Rhodes, plays an important role in the transfer, concentration and crystallisation of soluble salts.