On site tests for the mechanical characterization of masonry walls with chaotic texture

A campaign of on site experimental tests has been carried out for the mechanical characterization of the building stonework dated back to the 20’s – 40’s in the hospital complex of Volterra (Pisa). The presence of a disused masonry construction with mechanical properties similar to the surrounding buildings offered the opportunity to perform destructive and no-destructive tests and to extend results for the set of used buildings. The research deals with the comparison of several test methods on chaotic texture panels, to develop innovative test procedures to determine the best methodology for this particular masonry type. In this context, in addition to the conventional diagonal compression test, the Twin Panels Test (TPT) has been applied and developed. With the help of the various techniques employed (flat-jack, penetrometric tests), the failure mode of the panels under shear and compression forces has been interpreted and, starting from the observation of the results of the tests, the safety domain shear vs. compression for the rubber masonry typology has been drawn up. The cross validation of several testing techniques suggests strategies to determine the shear strength, deformation properties and ductility capacity of the walls with highly irregular texture. At the same time, the results are able to provide support for the calibration of the different NDT methodologies.