Earth masonries in the Medieval Grange of Cuna -Siena (Italy)

The Grange of Cuna was the administrative and storage centre of the bigger farm of Santa Maria della Scala Hospital in Siena. Built from the early '300 is characterized by continuous development of the building until the second half of the '700, when it was alienated. At present a plan of restoration is under preparation, for whose completion the following studies have been performed. The architectural survey, thanks to the accuracy of laser scanner technology added to a critical interpretation and data processing, represented the first knowledge of spatial and geometrical information and also gives a model useful to identify structural instabilities and deformations in order to direct the diagnostic phase. The stratigraphic investigations extended over the entire architectural complex made it possible to distinguish the historical constructive phases of the farm which original medieval nucleus was located in the southeast corner. Among the different masonries, in the medieval nucleus of farm fired brick masonries with earthen bedding mortars have been found, while in a post medieval addition rammed earth masonries plastered with lime mortar are present. Specific investigations such as endoscopies, thermographic analysis, sonic and double flat jack tests were carried out on each masonry typology. The results of the experimental activities together with the compositional characterization of the earth present in the masonries (mortar and rammed earth) are reported in the paper.