St. Lorenzo Basilica in Milan: Integral approach to characterisation of historical mortars

The work deals with an integral approach to the characterisation of historical mortars coming from the Basilica of St. Lorenzo. The monument, one of the most important of Milan (Italy), has undergone various interventions during the last centuries. At the occasion of a recent conservation work various techniques (optical microscopy on thin sections, X-ray diffraction, FTIR spectroscopy, thermal analyses, ion chromatography) were used in order to thoroughly analyse plasters and bedding mortars from the brick masonry. Investigations from various complementary points of view allowed the identification of the original components of the mortars, i.e. binder and aggregate fraction, and determination of the technology used. Moreover the nature of degradation compounds was elucidated, which enabled us to plan the optimal intervention.