Itria Valley (Apulia, Italy): Comparison of limestones for the construction and restoration of “Trulli” roofing

The high concentration and cultural relevance of dry-built constructions in a territory such as Itria Valley, in Apulia (southern Italy), which was designated a World Heritage Site by UNESCO in 1996, make such constructions especially valuable, and raise the matter of conservation through the accurate selection and treatment of natural stone materials. The original and traditional way of construction (more precisely, the roofing of trulli) relies on the use of flat stones, ‘chiancarelle’, which are commonly taken from local accumulations (‘specchie’) or quarried from shallow embankments. Recently, the trend has shifted towards the use of sawn stones, which are less expensive since they do not need to be shaped by artisans. The scope of this study is to compare the mechanical performance of chiancarelle and sawn stones, to find whether correlation trends can be found between the technological properties of such stones, and to assess whether ageing cycles can produce variations in the mechanical behaviour of sawn stones. Finally, the results obtained allow the identification of the tested material and its geological origin, as well as the correlation with mechanical and technological properties.