Late Baroque Towns of the Val di Noto (South-Eastern Sicily)

Petrographic, microstructural and petrophysical study of asphaltic limestone employed in the Late Baroque towns of the Val di Noto UNESCO site (south-eastern Sicily)

A petrographic, microstructural, and petrophysical study of asphaltic limestone (pitchstone) from the Late Baroque Towns of the Val di Noto UNESCO site reveals a strong correlation between bitumen impregnation levels and the material's distinctive visual properties as well as its superior physical-mechanical performance. The research employed advanced techniques such as synchrotron X-ray microtomography, ultrasonic testing, gas chromatography, differential scanning calorimetry, and thermogravimetric analysis to investigate two representative pitchstone samples with varying bitumen content. Findings demonstrate that the amount of bitumen impregnation directly influences both the petrofabric and petrophysical properties of the stone, offering insights into its durability and aesthetic characteristics in historic architectural applications.