Analysis of the earthen architectural heritage in Piedmont (northern Italy): typologies, construction techniques and materials

Piedmont is characterized by the presence of numerous earthen buildings mainly concentrated in the province of Alessandria. Studies conducted over the last decade, however, have shown the presence of interesting examples of these buildings also in the provinces of Asti, Torino, Biella and Cuneo. They are generally two-storied rural constructions, built with both fired bricks (for the bearing structures) and adobe (for internal and external walls). The case of the La Serra hills between Biella and Ivrea is particularly interesting because this zone, characterised by the presence of morenic terrains, is rich in stone materials and the traditional architecture is mainly characterized by the use of materials such as stone, brick and wood. Nevertheless, some interesting examples of earthen buildings have been found, evidence of the close relationships between man and his territory. They are fragile architectures, little or not at all known, which may be irretrievably lost if not properly safeguarded. The research aims have been to examine types and construction techniques and to analyze the characteristics and performances of the constitutive materials through in situ tests (rebound test), characterization of the adobe and mortars (XRD, particle size distribution) and identification of possible additives. This type of research will be useful to promote again the use in the area of these construction techniques, evidence of skills and abilities of people to take advantage of the local environmental resources.