Analysis, Diagnosis and Consolidation and Water Repellent Treatment of the Burgos Cathedral Stone

Abstract

A characterisation and alteration study of the Burgos Cathedral stone has been performed. In addition, the advantages and disadvantages of different consolidating and water repellent treatments applied to the stone were discussed. The chemical analysis suggests that the samples taken from the quarry and the monument consist of high-purity limestone (99.4% and 97.8% biosparite). The density, porosity, sorption-desorption behaviour, capillarity and permeability were determined. The obtained results showed the presence of free pores that facilitate the movement of water through stone. The mortars are mainly composed of SiO2 and CaO, with a high content of lime (calcite) and sand (quartz). The following alterations were found in the stone surface: patinas, black crusts, blistering, disaggregation, disintegration, efflorescence, surface deposits, chipping, alveolar erosion, fissuring and vegetation. The cartography of alterations was described. Four zones of white or washed stone, grey or dry deposits, black or wet deposits and green-yellow deposits were observed. The stones from quarries and monuments are treated with different consolidating and water repellent treatments that include silico-organic preparations, acrylic resins and fine mortar (‘jabelga’). The best results were obtained using ‘jabelga’. © 2015, Ecozone, OAIMDD. All rights reserved.