Keywords: masonry walls, non structural, bed joint reinforcement, numeric analysis.

Over the past decade, the design of building has changed: buildings are taller and more slender, designs favour larger spans, fewer pillars and the slab thickness has reduced; concrete structures have become more flexible, which requires a careful analysis of their deformations and consequences [1]; the walls were more rigid with the introduction of stronger and larger hollow blocks, which reduced the capacity of walls to absorb deformation [2]. However, beside the developments in design and the execution of the construction work, there are still problems with buildings. For example, masonry walls without structural function behave as a beam, resulting in cracks similar to those presented for the case of bending of reinforced concrete beams. This behaviour (masonry walls subject to in-plane bending) is due to the excessive deformation of the load bearing structure. Therefore, the aim of this paper is to study masonry walls without structural function and subject to in-plane bending. For this, masonry walls have been studied with bed joint reinforcement.

In order to evaluate the improvement of structural performance and efficiency of the proposed strengthening (reinforced masonry walls subject to in-plane bending), several numerical simulations of the mini-walls were carried out. The numerical analyses were carried out using the program DIANA 9.1, that uses the finite element method. The strategy adopted was macro-modelling of the non-linear physical behaviour. It was analyzed the behavior of the three types of mini-masonry walls, namely 400cm × 120cm × 14 cm; mini-walls without armor (as a reference); with armor at every two horizontal joints and with armor in all horizontal joints was analyzed. To analyze the behavior and efficiency of the reinforcement technique, the following issues were studied: the results at first cracking (the value of the total load applied and the deflection in the middle of the span, the distribution of stresses and strains); the behavior of the models during the application of vertical loads.

According to the results, models with armor at every two horizontal joints showed higher ductility and a slight difference in load capacity in comparison with the model with reinforcement in all horizontal joints. The results obtained from the numerical research proved that masonry walls with bed joint reinforcement show a higher first crack load, better performance in service, increased capacity and larger deflection at failure.

1

H. Medeiros, "Excessive deformations", Magazine Téchne, Brazil, 46-51, 13 April, 2005. URL

2

E.D. Bastidas, L.F. Molina, L. Yamin, A. Sarria, J.P. Ortega, J.G. Tumialan, "Non-structural masonry walls strengthened with GFRP laminates", North American Masonry Conference, South Carolina, USA, 2003.

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