Out-of-plane bending behaviour of masonry walls with high-strength steel cord mesh bed joint reinforcement

The study addresses the out-of-plane bending behaviour of masonry walls reinforced with an innovative high-strength steel cord mesh embedded in bed joints. The research includes an experimental program on masonry walls built with perforated brick units and lime-cement mortar, materials commonly utilized in the construction of exposed brick façades. Bending tests were conducted in accordance with standard EN 1052–2, with the aid of 3D stereoscopic Digital Image Correlation for precise analysis of out-of-plane displacements and crack tracking. The experimental study includes specimens with three different configurations, i.e. unreinforced masonry walls, walls with 0.6 m spaced reinforced bed joints, and walls with 0.4 m spaced reinforced bed joints. The experimental results exhibit a substantial enhancement of out-of-plane bending capacity and ductility due to the mesh configuration of the bed joint reinforcement, with high-strength chords distributed uniformly throughout the depth of the wall. The study proposes also an analytical model to describe the out-of-plane bending behaviour of this peculiar type of reinforced masonry, based on the mechanical properties and geometry of masonry components, and the amount of reinforcement. The research offers useful insights into the structural performance of a novel typology of reinforced masonry, providing a set of experimental results that can contribute to future research on the out-of-plane capacity of new technologies for the reinforcement of exposed brick façades. • Out-of-plane flexural behaviour of masonry walls with novel bed joint reinforcement. • Influence of the reinforcement amount and spacing on out-of-plane response. • Comparison of the results in terms of overstrength ratio, capacity, and ductility. • Remarkable increase of flexural strength, and of ductility with a gradual softening. • Proposal of an analytical model in agreement with the experimental results.