Experimental evaluation of the shear strength of aerial lime mortar brickwork by standard tests on triplets and non-standard tests on core samples

This paper presents the results of an experimental program carried out in the laboratory to evaluate the shear strength of aerial lime mortar brickwork. Masonry triplets and walls were tested after one year from their construction by adopting two different testing methods. The first approach consisted in the shear tests of masonry triplets, whereas the second technique was based on core drilling from walls of 90 mm diameter cylindrical specimens to be subjected to Brazilian tests with varying inclination of the diametric mortar joint. The first method is more adequate to characterize new masonry, whilst the second one is a suitable MDT procedure for the analysis of existing structures. The experimental results from standard and non-standard tests were properly investigated in order to obtain the shear failure envelope of the bond interface and mortar joint. The comparisons between the different tests and their interpretative theories show the possibilities of the novel non-standard testing method for the evaluation of the shear strength of structures of the built cultural heritage.