Study of vernacular building materials used in cultural heritage as a guide for architectural restoration: Colegio Maximo de Cartuja. Granada-Spain (19th century)

Colegio Maximo de Cartuja in Granada (Spain) was built by the Jesuits in 19th century. Using an archaeometric study of the building materials: bricks, glazed tiles, stained glass windows and lime-gypsum mortars (mortar masonry and concrete masonry), the vernacular concept of this construction was established within the geological framework of the "Alhambra formation", and raw materials and techniques first used by the Nasrids in the 13th century have been identified. The results of XRD, XRF and DTA analyzes indicate the use of local clays in the manufacture of bricks and tiles fired at temperatures of <= 750 degrees C. The clays contained NaCl additives, which improved the ceramic sintering, and traditional Nasrid colours (Cu, Fe, Sn) were used in the glazes and stained glass windows. Local raw materials were also used for air binders. These results have been combined to create a good-practice guide for the sustainable restoration of cultural heritage buildings.