1. Introduction
The deterioration of natural stone monuments is subject to different external reasons (Auger, 1991) through different weathering factors which are considered important phenomena especially with the presence of salty and moisten environments (Robert et al., 1992), in addition to other several factors concerning the stone itself, mainly pore structure and permeability index (Auger, 1996). Furthermore, the interactions between the atmosphere and invariably monumental stones lead to the formation of altered surface layers, producing damage to the original stone (Sabbioni, 1995), rocks and material exposed continually to physical, chemical and biological weathering processes (Fassina, 1991). Moreover, the degree and distribution of the types of observable stone deterioration in urban environments are often related to different patterns of wetting and drying cycles (Winkler, 1997; Chabas and Jeannette, 2001), in addition to the exposure of the stone surface to driven rain (...
