Speaker
Description
Rising damp is one of the main degradation mechanisms affecting historic masonry buildings and represents a major challenge for the conservation of cultural heritage. The assessment of rising damp is intrinsically complex due to the heterogeneous nature of masonry and the strong interaction between absorption, transport, and evaporation processes. Conventional diagnostic approaches are often based on invasive sampling or gravimetric measurements, which are poorly suited for in situ investigations and are generally incompatible with the requirements of cultural heritage conservation. Consequently, there is a growing demand for non-destructive techniques capable of providing quantitative information on moisture transport while preserving the integrity of historic structures.
Within this framework, Quantitative InfraRed Thermography (QIRT) offers a promising non-destructive alternative, as it enables the observation of surface thermal patterns associated with moisture-related phenomena. Variations in surface temperature are strongly influenced by evaporation processes occurring in wet areas, making IR thermography particularly suitable for detecting and monitoring moisture in porous building materials.
The present contribution represents the continuation and methodological advancement of the work presented by Guolo et al. (2024), in which passive IR thermography was applied to the monitoring of moisture diffusion and capillary rising damp in masonry materials. Building upon those results, this study aims to establish quantitative correlations between capillary rise parameters derived from thermographic analysis and the physical properties of the materials, with the objective of advancing toward a standardized and fully non-invasive diagnostic methodology suitable for in situ applications.
Experimental investigations were carried out on clay bricks commonly employed in restoration interventions and representative of traditional Venetian architecture. The materials were characterized through measurements of bulk density, porosity, and capillary water absorption, obtained using standardized laboratory procedures. Capillary rise experiments were performed under controlled environmental conditions and monitored using passive IR thermography.
The recorded temperature data allowed the qualitative identification of dry and wet regions and the quantitative tracking of the wetting front progression, enabling the determination of characteristic parameters such as the inflection point and the rising velocity of the capillary front. The temporal evolution of the rising damp front derived from IR analysis exhibited a square root of time dependence.
The results demonstrate that passive QIRT can provide quantitative information on capillary moisture transport without the need for direct contact or gravimetric measurements. The proposed approach represents a further step toward the standardization of IR thermography for the in-situ assessment of rising damp and supports its application for long-term monitoring and preventive conservation strategies in historic masonry structures.
