Correlation between ultrasonic measurements and mechanical testings: a methodology applied to D'Amico Palace of Milazzo

摘要

This research is a part of a diagnostic work that was carried out on PalazzoMarchesi D'Amico of Milazzo in Sicily. The results of the diagnosis are nowgoing to be used as base for the conservation project.Aim of this work is to find correlation between the results of ultrasonicmeasurements obtained on two columns of the palace and the mechanicalcharacteristics of constructional materials, taking also into account theiranisotropy, in order to obtain information on the mechanical behaviour ofthe two columns in a non destructive way.The constituent materials of the columns are sandstone, of a type called inSicily "arenaria". The material was analysed by means of the followinganalytical techniques: X Ray Diffraction, observation of cross sectionsunder the optical microscope, analysis at the Scanning Electron Microscope.Longitudinal velocity at the frequency of 50 KHz was measured on threesections at different heights of the two columns. A tomography analysis wasdone on a section of a column. Since it was not possible to take sample fromthe columns to carry out the mechanical testing, were founded a cave fromwhich was token three different blocks of arenaria that was similar, but nonequal of course with respect the material of the columns. The difference wasdetected both by ultrasonic measurements and by petrographycal observations.Compression mechanical tests have been performed on the material of the caveand static and dynamic modules (obtained at 1 MHz) were compared.This study is devote to set up a suitable methodology for studying themechanical behaviour of the material of the analysed particular of themonument, to apply when it is not possible to carry out mechanical testingdirectly on the same material and to optimise the number of tests on thesame material, considering the low availability of materials in theconservation activities.