Consolidation treatments applied to ceramic tiles: are they homogeneous?

Abstract

ABSTRACT:The mass consolidation treatment of azulejos is necessary when ceramic biscuits show signs of disaggregation. Such treatment is often used as a complementary conservation technique to the reestablishment of weakened glaze-ceramic bonds. In this research, two commonly used consolidants (ethyl silicate and acrylic resin) were tested on artisanal ceramic tiles via mass consolidation and the resulting impregnation profiles were evaluated. The results indicated that after consolidation, hard zones frequently formed due to localized consolidant concentration after the polymerization and curing processes. These inhomogeneous hard zones subsequently influenced the results obtained through conventional mechanical strength testing (i.e. flexural and compression), creating a false impression of success. This research demonstrated that by using the Drilling Resistance Measuring System, impregnation characteristics such as penetration depth and distribution of consolidant could be observed that otherwise could not be discerned through the more common testing methods. As such, a more extensive evaluation of consolidation effects was achieved. RESUMEN: Tratamientos de consolidación aplicados en materiales cerámicos: ¿Son homogéneos?En la conservación de los azulejos alterados se utilizan productos con acción consolidante a fin de recuperar la cohesión del cuerpo cerámico disgregado. En este trabajo se investiga el efecto de la consolidación de dos productos muy utilizados en la práctica de la conservación de los azulejos (un silicato de etilo comercial y una resina acrílica), aplicados en un material cerámico artesanal. Los resultados obtenidos indican que pueden producirse zonas con resistencias mayores debido a la concentración local del producto y, a la vez de un material consolidado homogéneo, resulta un material heterogéneo. Por otro lado, la existencia de estas zonas puede conducir a falsos resultados en los ensayos destructivos (resistencia mecánica a la flexión y compresión) utilizados frecuentemente en la evaluación de la acción de consolidación. Se demuestra que mediante el uso de la resistencia a la perforación (DRMS) es posible definir las características, la distribución y el patrón de impregnación, los cuales no pueden ser observadas por los métodos comúnmente utilizados.

Adhesion of Historic Tile Fragments in Outdoor Architectural Settings

“…The fracture of the tiles can also be provoked by other mechanical actions, such as external impacts and stresses due to deformations of the wall. Despite the importance of this heritage, and the fact that many tile panels are at risk of being lost due to lack of or improper conservation issues, the studies dedicated to the procedures and materials [12][13][14] for their conservation such as consolidation treatments [15][16][17][18][19][20], desalination [21,22], glaze lacunae infill [23][24][25][26], and retouching [27] remain relatively scarce. Regarding adhesives, many types have been or are being used in the restoration treatments of outdoor-located tiles.…”

Evaluation of effectiveness of silicoorganic treatments using hydric properties

“…before and after applying several treatments were analyzed. These types of analyses have also been carried out by several other authors (Hammecker et al, 1992;Valdeon et al, 1992;Vicente, 1996;Villegas-Sánchez and Espinosa-Gaitán, 2001;García-Garmilla et al, 2002;Berardi et al, 2002;Espinosa-Gaitan et al, 2002;Quaresima et al, 2002;Alcalde-Moreno et al, 2003;Buj and Gisbert, 2006;Luque et al, 2008;Torrisi, 2008;Alejandre and Villegas, 2009;García et al, 2010;Rivas et al, 2011;Galvana et al, 2014;García-Talegón et al, 2015, 2016aArezki et al, 2016;Costa et al, 2017). In addition, Martín et al (2002) designed an instrument that allows a wide range of temperatures to be maintained and controlled automatically using a computer.…”