Characterization by X-ray computed tomography of water absorption in a limestone used as building stone in the Oviedo Cathedral (Spain)

Abstract

Water plays a fundamental role in rock weathering processes. Its penetration and movement inside rocks greatly influences the nature and intensity of damage affecting building stones. X-ray computed tomography (CT) is a useful technique for non-destructive mapping of water penetration. For the reported study, CT was used to investigate the internal structure and water penetration patterns for the Piedramuelle Stone, a Cretaceous limestone used as building material in the Oviedo Cathedral (North of Spain).X-ray CT provides good images of the internal structure of the samples: the sedimentary layering due to differences in composition and porosity is clearly seen, as well as other textural features. The movement and penetration rate of water was monitored during standard free absorption water tests. The images that were obtained show a clear difference between dry and wet zones in the interior of the sample. Water movement is related to the petrographic characteristics of the rock, mainly to layering which controls the direction of water penetration. Hounsfield Unit numbers provide a quantitative approach for assessing the penetration rate of water.

Laser Scanning Confocal Microscopy Characterization of Conservation Products Distribution in Building Stone Porous Network

“…In order to correctly interpret the effect of these products, it is essentially to know the initial configuration of the porous network and the spacial distribution of conservation products. SEM-EDX and X-ray micro-computed tomography, combined with specific 3D software, had been employed to determine the impregnation depth and distribution of consolidants and water repellents in several building materials (Ruiz de Argandoña et al, 2003;Mees et al, 2003;Cnudde et al, 2004;De Vetter et al, 2006;Rodríguez-Rey et al, 2006). Nevertheless, this arrangement of techniques is not easily available and is presently limited to detect pores larger than 10μm.…”

Ensayo de capilaridad en areniscas monitorizado mediante tomografía computerizada de rayos X. Estudio comparativo con métodos convencionales

“…CT or CAT scanning is a very useful non-destructive technique for studying rock porosity (5,6) and the movement of fluids, water among them, in inside rocks (7)(8)(9)(10); it has also been used in studies related to other types of rock alterations (11)(12)(13)(14).…”

“…La TAC es una técnica no destructiva muy útil tanto para estudiar la estructura y/o el espacio poroso de la roca (5, 6) como el movimiento de fluidos, entre ellos el agua, en su interior (7)(8)(9)(10); también se viene aplicando recientemente en otros estudios relacionados con la alteración de rocas (11)(12)(13)(14).…”

Laser scanning confocal microscopy characterization of water repellent distribution in a sandstone pore network

“…These studies presented superficial 2D images of treated samples only as an illustration of the distribution of the water repellent in the rock. SEM-EDX and X-ray microcomputed tomography, combined with specific 3D software, had been employed to determine the impregnation depth and distribution of consolidants and water repellents in several constructive materials (Cnudde et al, 2004;De Vetter et al, 2006;Mees et al, 2003;Rodríguez-Rey et al, 2006;Ruiz de Argandoñ a et al, 2003). Nevertheless, this arrangement of techniques is not easily available and is presently limited to detecting pores larger than 10 lm.…”