Research of correlations between NDT and DT to assess mechanical properties of a soft stone in ancient masonry

A deep knowledge of the physical and mechanical properties of the constituent materials of ancient masonries is of crucial importance in the choice of the proper intervention technique. In case of historical buildings sustainable diagnostic procedures responding to the conservation constraints, should have the lowest degree of intrusion and the fullest respect for their physical integrity. The sample’s extraction from existing structures for laboratory tests is one of the major problems in the field of diagnosis of ancient buildings and this has moved the scientific community to propose alternative non-destructive techniques to evaluate the mechanical and physical properties of the building stones. In the present work non-destructive and destructive tests have been investigated as tools for assessing the compressive strength of “Lecce stone”, a soft calcarenitic stone used as traditional building materials in the Southern Italy. Ultrasonic pulse velocity (UPV), Schmidt hammer test and compressive tests on microcores have been compared with mechanical destructive tests on cubes in order to found correlations between the results. The final aim is to assess the reliability of the non-destructive investigated methods in describing the mechanical performance of the stone, reducing the use of destructive analyses on masonries.