On site and laboratory investigation on the 16th-17th century masonries: the Foxi defensive tower (Cagliari Gulf, Sardinia, Italy)

This study is part of an ongoing research aimed to examine a number of important defence towers situated along the Sardinian coast, Italy. In this paper we present the investigations of the Foxi coastal towers in the Cagliari Gulf. It has been studied through the analysis of masonries (ashlars, plasters and mortar) by an historical, architectural, technical and petrographical-chemical point of view, through a methodology based on a stratigraphical approach. The aim of this research is the understanding of the traditional building techniques used during the 16th-17th centuries, combining dating strategies, with four different principal objectives: i) put in evidence the peculiarities of the traditional building techniques used during this period; ii) increase the knowledge of the constructions and their degradation phenomena to warranty proper restoration; iii) identify different stones and component materials used for the mortar for the determination of binder/aggregate ratio and to determine the level of weathering of stones and mortars; iv) facilitate, on the basis of acquired data, the dating of other contemporary edifices, especially referring to the socalled minor buildings, which are very often object of inappropriate restoration