Fracture mechanics in the characterisation of brick masonry structures: Fid-Bau Portal

Fracture mechanics in the characterisation of brick masonry structures

Olivito, R. S. / Stumpo, P.

Abstract The analysis of the mechanical behaviour of masonry structures is based on the assumption that this material does not withstand tension. In this field many researchers are studying how to refine analytical and experimental procedures to obtain a more accurate correspondence between the real behaviour and the simulated one. However, this hypothesis cannot explain the masonry strength with respect to dynamic and seismic load conditions, which cause tensile stresses and dilating strains in masonry structures. The aim of this work is to give a complete set of experimental results in order to determine the mechanical properties of brick masonry. In particular, an extensive experimental programme was carried out to characterise the mechanical and structural behaviour of masonry composite in compression, along both the material directions, and in tension, along the horizontal mortar joint direction. Tensile properties in particular were estimated by means of four-point bending (FPB) tests owing to the lack of a standard tensile test and because bending tests are considered to be reliable indirect tensile ones and easy to carry out. The experimental results obtained using this testing procedure highlighted the behaviour of a bimodular material when subjected to tensile stresses, and these were then analysed by means of fracture mechanics theory to estimate the masonry toughness and stress intensity factor as further material characteristics.