(Dipartimento di Ingegneria Civile, Ambientale e Architettura – University of Cagliari, Italy)

Keywords: non-destructive analysis, terrestrial laser scanner, ultrasonic techniques, petrographic analysis

This paper describes the results of a survey aimed to use a non-destructive methodology based on the integrated application of 3D terrestrial laser scanning (TLS), acoustic techniques and petrographycal analysis in evaluating the quality of cultural heritage structures.
The application of a methodology useful to evaluate the quality of stone building materials and locate altered or damaged zones both in shallow and inner parts of the investigated architectural elements is presented in this study based on the integrated application of three independent techniques, two non destructive such as the terrestrial laser scanning and the ultrasonic techniques in the 24kHz – 54kHz ultrasonic range, and a third to analyze the petrographical characteristics of the stone materials, mainly the texture, with optical and scanning electronic microscopy (SEM). A very interesting case study is presented on a carbonate stone door of great architectural and historical interest, well suited to a high definition survey. This architectural element is inside the “Palazzo di Città” museum in the historical center of the Town of Cagliari, Sardinia (Italy). The integrated application of TLS and in situ and laboratory ultrasonic techniques, enhanced by the knowledge of the petrographic characteristics of the rocks, improves the diagnostic process and affords reliable information on the state of conservation of the stones used to build it. The integrated use of the above non destructive techniques provides useful data in assessing and monitoring the status of the investigated monumental structure and in planning its restoration.
Acknowledgements: We thank the Cagliari Town Hall and the management of the Civic Museum Antico Palazzo di Città for their kind permission to work on the Museum. This work was supported by Regione Autonoma della Sardegna (Sardinian Autonomous Region), Regional Law 7th August 2007, no. 7, Promotion of scientific research and technological innovation in Sardinia.