Modelagem computacional para avaliação do efeito do não preenchimento das juntas verticais na resistência da alvenaria estrutural

Abstract

Masonry is a composite material, consisting basically of units and mortar joints (vertical and horizontal), and may also be associated with other materials, such as steel and grout. In Brazil, from the 1980s, structural masonry consolidated itself as a highly productive, rational and economical construction system due to characteristics as: simplification of execution techniques, less diversity of materials employed, reduction of labor and speed execution. In structural masonry, one of the execution possibilities that can be explored is the non-filling of vertical joints, also called dry joints. The adoption of this practice generates certain advantages as the reduction in the execution time of the construction, the reduction of the consumption of materials and the minimization of the cracking caused by the intrinsic deformations, such as retraction and thermal deformations. However, despite be employed to some years in country, the implications of its use often has been not properly considered in the projects, this is due to the fact that there is few research that deals with this subject. Moreover, the existing researches sometimes present results that diverge from each other, mainly with respect to the resistance to compression and shear. In this work, numerical simulations of small walls of ceramic and concrete units, with and without vertical joints, tested with the requirements of NBR 15812-2 (ABNT, 2010), NBR 15961-2 (ABNT, 2011) and NBR 14321 (ABNT, 1999). The purpose of this work was to evaluate the influence of non-filling of vertical joints on the compressive strength and shear strength of the masonry. For the numerical analyzes, the Finite Element Method was used from DIANA® software. According to the numerical results obtained in the models in compression, and the comparison between these and the experimental results, it was possible to conclude that the absence of the vertical joints did not influence the compressive strength of the masonry. However, from the results obtained in the shear models, it was concluded that it was not possible to quantitatively evaluate the influence of the vertical joints on the shear strength of the masonry.