Construction and Building Materials 17 (2003) 557–571 0950-0618/03/$ - see front matter  2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.conbuildmat.2003.08.007 Characterisation of the materials used in the construction of the Noto Cathedral G. Baronio, L. Binda*, C. Tedeschi, C. Tiraboschi DIS – Politecnico of Milan, Milan, Italy Received 3 December 2001; accepted 15 August 2003 Abstract After the partial collapse of the Cathedral of Noto, the authors were required to carry out an extensive on site and laboratory investigation in order to support the designers of the Cathedral reconstruction to check the possibility of preserving the parts which are still standing and to choose the right solutions and the most compatible materials for the reconstruction. The tests carried out in laboratory in order to characterise the chemical, physical and mechanical properties of the original materials are described and their results discussed.  2003 Elsevier Ltd. All rights reserved. Keywords: Materials; Stone; Mortar; Chemical tests; Mechanical tests 1. Introduction The Cathedral of Noto dedicated to S. Nicolo was ` built after the earthquake which hit the eastern part of Sicily in 1693. Its plan was a three nave basilica structure in the shape of Latin cross. A dome resting on a tall drum was supported by four large arches at the centre of the transept. At present the facade in a beautiful baroque style, as the whole church, has remained intact while in the interior there are the dramatical signs of the collapse which occurred in March 13, 1996. That day the central and part of the right lateral nave here collapsed together with a large part of the dome (Figs. 1 and 2). An extensive investigation was carried out on site by the authors w1x in order to study: (i) the morphology of the walls and the pillars, (ii) the state of damage of the remaining pillars of the central nave, (iii) the possibility of preserving them by appropriate strengthening and repair, (iv) the possibility of consolidation of the walls and of the pillars by the grout injection technique. In the meantime a parallel accurate work was done in laboratory in order to identify and characterise the *Corresponding author. Tel.: q39-2-2399-4318; fax: q39-2-2399- 4220. E-mail address: binda@rachele.stru.polimi.it (L. Binda). materials used in the construction of the load-bearing and non-bearing elements. The aims of the research were the following: (a) To detect, through the characterisation of the materials, their composition and their mechanical and physical behaviour in order to understand the material role in the collapse. The pillars had an external leaf of cut stones and rubble masonry in the interior. The mortars in the core of the collapsed pillars presented for example diffused cracks (Fig. 4) and a very weak and fragile appearance. The stones of the external leaf of the pillars were regularly cut and resting on thin mortar joints. Two types of stones were found: a calcarenite called ‘Noto stone’ at the base up to 1.50 m, a ‘traver- tine’ from above the base to the top. It was important to characterise the two materials from the physical and mechanical point in order to compare their properties and to find the difference between them and the internal conglomerate. (b) To provide the structural engineers the parameters, for the implementation of the structural models, and therefore the mechanical properties of the masonry and of its components (strength, elastic moduli, etc.). It was particularly important to define the properties of the mortar, the weakest material in the structure. In collaboration with the designers and the consultant structural engineers and according to the assumed math-