Sustainable Assessment: A Contribution to Improve the Reliability of NDT on Old Chestnut Purlins

Abstract

The aim of this study is to give an additional contribution to the improvement of a sustainable diagnostic practice to be used for the assessment of ancient wooden structures, in order to limit the damage of the existing ones through destructive tests, and to have a reliable prediction of old element properties, with their historical value, reducing demolition and substitution with consumption of new materials. To achieve this purpose, correlation laws and methodologies that can be used to facilitate the performance of non-destructive testing (NDT) in situ, will be highlighted. Seventeen chestnut purlins, dated between the 19th century and the 20th century and coming from the roof of the Cloister of Michelangelo at the Baths of Diocletian in Rome, are tested. As the first part of a wider experimentation, the aim is to identify the best practice for three relevant unknowns that characterize a wooden structural element: the geometry, through the survey and the BIM modelling; the density by means of the penetrometric tests (Resistograph and Woodpecker); the elastic module through direct and indirect ultra-sonic tests.