ND tests for a first assessment of mechanical behaviour of the stone-covered façades of Palazzo Ducale in Venice

A program of non-destructive tests carried out on the two medieval stonecovered facades of Palazzo Ducale in Venice is here described. It consisted of direct and indirect sonic wave velocity tests on site and direct tests in the laboratory on samples of the component materials. The program was set up after a preliminary historic investigation aimed to raise useful clues on the geometric, physical and mechanical features of the double-layered facades. The qualitative information provided by the sonic testing procedure was assessed by mutual comparison of the results; the reliability of the collected data was also kept into consideration by assessing the distribution of results. The reported information is going to be one of the first steps in a wide programme of multi-disciplinary control of the facades.