Onsite diagonal tests on masonry panels

Diagonal tests are carried out to determine the shear strength of masonry for attainment of its tensile strength limit. The test consists in isolating a square panel from a building wall, realizing four cuts on its corners with diamond wire or a circular saw. Test on site is different from that in laboratory for the lower part of the panel which remains connected to the masonry wall, with negligible influence on the results. The diagonal compression is applied by hydraulic jacks located on one edge of the panel: a purposely designed steel frame transfers the compression force at the opposite end of the panel. During the test the relative displacements of the panel diagonals are acquired through displacement transducers positioned on both sides. The test generally ends with a fragile collapse (splitting) of the panel. Reference standard: ASTM E 519-07.