Structural behaviour of contemporary vaulted spaces with complex ashlars: the Abeille’s sail vault

The aim of the research is to investigate the static and dynamic behaviour of contemporary vaulted spaces, generated by the Flat Vault of Abeille patented in 1699. In fact, its reinterpre-tation and its use in architecture can both enhance the existing architectural heritage and char-acterize the new construction of building through the use of traditional construction materials and techniques. It follows that the identification of this “new type” of vault is essential to de-sign it correctly and to optimize the geometry for structural purposes. The Abeille-Type ashlar is a polyhedron that has two axial sections, in the shape of an isosceles trapezoid, oriented in opposite directions. The arrangement of the ashlar takes place in the two orthogonal directions creating a bidirectional flat plate, with a single type of optimized ashlar, whose geometry guarantees the mutual support of the individual blocks of the vaulted system, once assembly is complete. Starting from this ashlar and applying its deformation on curved surfaces, it is therefore possible to design “contemporary” types of vaults, characterized by complex ashlars in order to optimized both an aesthetic-formal and a structural function. The research proposes to apply already consolidated structural analysis methodologies – on traditional vaults – on this structure and describes the results of an experimental with quasi-static tests on a 1:8 small-scale vault model made of 3D printed blocks assembled with dry joints. In particular, shear in-plane and tilting tests were carried out by means of manual ac-tuators and controlled with incremental displacements. Different configurations are investi-gated both for the shear failure (simple or pure shear) and the tilting collapse (different in-plane angle). The results experimentally obtained were analysed in terms of damage/collapse mechanisms, strengths capacity and ultimate displacements. The Distinct Element Method (DEM) will be used for the numerical analyzes, being until now the most accurate and realistic for masonry structures, since it can take into consideration their discontinuous nature and the interlocking/toothing of the individual elements. In fact, it allows to investigate the vault ashlars as rigid and separate entities, witch interact with each other through the block planar interfaces; so the stability and the deformation of the whole vault is managed by the join contacts. Both experimental and numerical results furnish important data to formulate the behaviour of this vault. After the validation the results are extended to a full-scale vault by means of the similarity criteria, whose efficacy in the generalization of the results from the model to the prototype is demonstrated. In this way, the model can be finally adopted to simulate the be-haviour of a contemporary vault with the Abeille-Type ashlars.