Differential damage in the semi-confined Munazio Ireneo cubicle in Cagliari (Sardinia): a correlation between damage and microclimate

Abstract

The Early Christian Munazio Ireneo cubicle in Cagliari (Sardinia) is carved into the rock and is one of the rare monuments of Sardinia belonging to Early Christian Age. It is 166Â cm under the planking level and is a semi-confined chamber in which a gate allows exchange with the outside. In 1888, when it was discovered, it was completely painted, but over the years, it suffered a serious damage and all the paintings are nearly disappeared. Now the site shows a high moisture and a differential damage characterised by delamination, powdering, salt crystallisation and biological colonisation. The research offers a multidisciplinary approach to study the salt crystallisation damage, which is a phenomenon still not completely understood today. Studies and analyses highlight that different kinds of damage can be recognised. The cement mortar and the air pollution cause crystallisation of the sulphates. Constant capillary rising and the presence of water infiltration due to the rains, which travelled into the site from the vault, were detected during qualitative inspection. Although the microclimate did not change much in the site and the humidity was almost constant during the monitoring period, the variations in temperature allowed the phase transitions of sodium sulphate, especially in summer. The greatest damage of the porous stone is associated with the phase transitions and crystallisation inside the stone of sodium sulphate, one of the most harmful salts for porous materials because of its high crystallisation pressure

Black Fungi and Stone Heritage Conservation: Ecological and Metabolic Assays for Evaluating Colonization Potential and Responses to Traditional Biocides

“…These values can be explained with the time of outdoor exposition (1876 RR, 1890 AV, and 1900 FGM their years of built) and even more by microclimatic conditions. Previous studies showed that the most damaged marble pieces in the cemetery of Cagliari were all characterized by low values of solar radiation, high humidity and a reduced thermoforesis, favoring sulfatation and weathering along with the surfaces' colonization [32,33,67,68]. Indeed, the nearby and dense vegetation, in addition to the low exposition to the dominant winds (Libeccio and Scirocco from south and Mistral from north-west), favored the stagnation of marine air and its penetration into damaged stones.…”

Climate Change Threats to Stone Cultural Heritage: State of the Art of Quantitative Damage Functions and New Challenges for a Sustainable Future

“…Climate change and its consequences are becoming mandatory issues to be tackled by international and local authorities in charge of risk assessment and responsible for taking actions to mitigate their effects: this is true not only with regard to the environment, but also with respect to cultural heritage. Indeed, the combined action of natural weathering agents (e.g., rainfall, fog, snow, or salts) and atmospheric pollutants derived from anthropogenic activity drastically changes the material-atmosphere interface, causing the loss of the surface material and, consequently, the loss of its aesthetic quality [2][3][4][5][6].…”