Diagnostic characterization and temporal sequence of the masonry’s mortars from the foundations of Santa Maria del Fiore Cathedral (Florence -Italy).

The aim of this paper was mainly to characterize the composition of the mortars of the ancient foundations masonries from Santa Maria del Fiore Cathedral. This characterisation was finalized to individuate the temporal sequences of the building materials inside the crypt. The mortars of the crypt were sampled in the same positions as reported in a previous works by L. Marino [1], in order to emphasize analogies and/or differences in comparison with past architectonical studies. Mineralogical-chemical and petrographical analyses (XRD, FT-IR, OM) were carried out in order to characterize the composition and the texture of the mortars [2] and to discriminate the different typologies of masonries. The data showed the presence of two main mortars groups and therefore two types of masonries. These results suggest two different building phases, in contrast with the previous architectonical studies by Marino. Besides, the analyses allowed to evidence bad conditions of alteration of the masonry, due to strong nitrates concentration because of the presence of many sepulchres inside the crypt.