Celeste Almeida

Characterization and Reinforcement of Stone Masonry Walls

Stone masonry is one of the oldest “structural materials” known to man. It is made by the superposition of stones, mortar and, very often, with infill material between leaves. The components present complex links and interactions and, in most cases, unknown geometry and high variability of their mechanical properties. These characteristics make stone masonry a highly heterogeneous material for which it is difficult to define realistic behaviour laws, a challenge that still demands further research, either through laboratory or onsite experimental campaigns. In reality, the mechanical characteristics of a stone masonry element strongly depend on the geometry and geometrical distribution of the stones along the facade and cross-section of the element and, therefore, on the layout of the interfaces, i.e. the joints. Studies developed in Italy have defined a series of parameters that try to quantify the level of fulfilment of good practice constructions rules with the expectable performance of a stone masonry wall under static and dynamic loading, in particular under seismic type loadings. This chapter discusses construction typologies and materials, assessment methodologies, earthquake induced failure mechanisms and strengthening intervention techniques on stone masonry structures, in particular walls.

A Novel Approach to the in situ Compression Testing of Stone Masonry Walls

Masonry structures constitutes the urban core of several cities throughout the world, justifying the interest for the development of new testing techniques, capable of characterizing their main mechanical properties. The present paper approaches the in situ testing of stone masonry walls, describing the steps that led to the definition of a new compression test set-up. Said set-up was devised to be a modular and adaptable system, capable of being used in different types of walls, with different textures and unit types. Being self-balanced, the hereby-proposed scheme doesn´t introduce any new external loads into the whole building producing, at the same time, a uniform compression load. Throughout the paper, the peculiarities of masonry structures are mentioned, in order to justify some of the considerations taken into account in the development of the system. The results of an experimental campaign performed in an abandoned building in Oporto (Portugal) are presented, showing the outputs that can be extrapolated from the procedure, namely the characterization of the cyclic behavior of the walls and its deformability parameters.