ESTUDO DO CISALHAMENTO EM LAJES ALVEOLARES PROTENDIDAS

Abstract

Accompanying the 9.7% growth in 2021 in the civil construction sector, the precast industry has shown a large increase in demand for prefabricated structural elements. The use of prestressed hollow core slabs contributes, for example, to the design of buildings that have spaces with larger spans and more integrated. Thus, knowing and studying the characteristics of prestressed hollow core slabs is fundamental. In view of this, one must know its behavior when subjected to forces, especially in relation to shear. For this, 15 slabs arranged in the study of 5 authors were chosen for analysis. In general, this work seeks to estimate the shear strength for prestressed hollow core slabs, using 3 equations - namely: the equation available by ABNT NBR 14861:2022, the equation provided by Eurocode (EC-2-1-1 :2004), and finally, the analytical form proposed by Sales, Ferreira and Araújo (2022), which includes other factors such as inertia in its calculations, seeking greater assertiveness and refinement of the results. Slabs of different heights are studied using these equations. Slabs with heights above 320 mm also showed bending failure in the works, which can be evaluated using these equations that are characteristics of bending failure due to shear. Determining the most effective method can positively contribute to designers being able to design elements with a good cost/safety ratio. Through the analysis of these 15 slabs tested and present in the bibliography, it could be concluded that the equation proposed by Sales, Ferreira and Araújo (2022) is efficient in terms of dimensioning the shear force studied and that, in addition, it can be used for dimensioning of such forces for slabs with heights greater than 320mm.