Mortars: a complex material in cultural heritage. A multi-analytical procedure to characterize historical mortars.

This thesis deals with the identification of mortars composition in a cultural and historical context. In detail, the main concern was to collect information for proposing an analytical procedure able to define the mortar typology, balancing advantages, drawbacks, time and costs. In addition, several new techniques have been recently introduced in conservation science and the aim of this research is also to consider these new competences too. To understand the interactions between components of mortars, in Chapter 1 a general overview of the subject is given with a description of the materials and of the historical background, based on the review of the large bibliography taken into account. In Chapter 2 the methods used for the preparation of the model samples and the final composition are explained. Moreover, the analytical techniques used in this research (optical microscopy and petrographic analysis, powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy, environmental scanning electron microscopy, thermal analysis, mercury intrusion porosimetry and computed tomography) are described, specifying the setting of the instruments. In Chapter 3 the results of the characterization of the raw materials and of the model samples are shown, the most meaningful results are shown for each technique. The discussion of the experimental data is presented in Chapter 4, and some analytical protocols are proposed, described and explained. In the last chapter, Chapter 5, the conclusions and the future development of this research are underlined.