ABSTRACT
ABSTRACT: The most common and relevant stone material found in emblematic monuments of the Built Heritage of Córdoba (Spain) is a porous calcarenite. The quarries of this material include shallow facies arranged in sandstone and calcarenite packs with different amount of detrital component, containing a large proportion of clay minerals, which makes them highly sensitive to processes of decay related to environmental changes (e.g., changes in relative humidity). In order to establish the presence of swelling clays, as well as their potential role in the weathering of this type of stone, samples from the Palacio de los Páez de Castillejo and three types of stone from Madinat Al-Zahra (Córdoba) were studied. Analyses revealed that the amount of clay minerals was about 5-30 wt%. A high content of swelling clays (smectite and chlorite-smectite mixed layer) was detected, which in addition to the overall high porosity of the stone, appears to be highly detrimental.
