X-ray micro-CT used for the localization of water repellents and consolidants inside natural building stones

Natural stones used in monuments have to deal sooner or later with weathering. The desire to preserve cultural heritage created a wide variety of products to reduce the rate of stone decay and to strengthen decayed stone. The ability of these water repellents and consolidants to penetrate inside natural building stones is one of the main factors controlling their performance. The determination of this penetration depth is crucial for the application of conservation products. Because the impregnation depth also depends on the characteristics of the material itself, such as total porosity and pore size distribution, these should be considered when restoration is planned. X-ray micro-computed tomography (μCT) was used to determine the impregnation depth of water repellents and consolidants. 3D information about the total porosity and the pore size distribution was obtained with the combination of μCT and home-made 3D software. This experiment should provide a basic step for extra advice on the suitability of products for the treatment of a particular rock type.