The evaluation of masonry shear strength by means of different experimental techniques: A comparison between full-scale and laboratory tests

Seismic vulnerability of masonry structures was recently confirmed, if necessary, by last earthquakes who stroke in Italy some years ago. As a consequence, great efforts are actually devoted to the assessment of the masonry built heritage; in this framework, the definition of shear capacity of masonry is of paramount importance, even though the available experimental techniques are often too invasive (full destructive tests) or provide for really scattered results (non-destructive tests). Present work analyses the possible correlation among masonry shear mechanical parameters obtained from different types of destructive and moderately destructive tests. To this purpose, an experimental campaign on full-scale masonry samples built using hydraulic-lime based mortar and clay bricks, was carried out and described in this paper. At the same time, a number of laboratory tests on smaller specimens and cores made of the same masonry were also considered. Diagonal compression tests were carried out on double-leaf masonry panels while direct shear tests were conducted on single-leaf masonry specimens and triplets; finally, cores (cored from panels) were subjected to splitting test with different mortar layer inclinations. Comparison of first results suggested the quality of correlation between different experimental tests, when both shear sliding and diagonal tensile failure modes are considered.