Methodology for on site evaluation of physical and mechanical properties of historic masonry

The last earthquakes in Italy allowed once more to learn that the lack of knowledge on the morphology and on the mechanical behavior of bearing masonry elements is the main cause of inappropriate choices for intervention. The paper wants to propose a methodology for the analysis of the historic load-bearing stone masonry. One of the worst structural defects of a masonry wall is the lack of monolithic behaviour under horizontal actions due to poor quality, e.g. when the wall is made by multiple leaves not mutually connected. The proposed methodology is a step by step procedure of data collecting developed within the Italian Research Project RELUIS in order to reach an evaluation of the masonry quality for structural purposes (as requested by the Italian technical code) with the help of Non Destructive techniques, and to support appropriate intervention strategies. More in detail, the proposed procedure includes: (i) masonry texture survey, (ii) sonic pulse velocity test, (iii) single and double flat jack test, (iv) direct visual inspection of the masonry section and details by local dismantling, (v) material sampling and characterization by laboratory tests.