Análise da influência do fator de fragilidade ηc no dimensionamento de vigas e pilares de concreto armado, com base na norma NBR 6118:2023 e o projeto de norma EN 1992-1-1:2022

Abstract

In light of the recent update Brazilian to the Concrete Structures Design Standard, NBR 6118:2023, which introduced significant modifications regarding the design of high-strength concrete elements, this study presents a comparative analysis of beam and column design, comparing the 2014 and 2023 versions of the standard with Fpr EN 1992-1-1:2022. The ultimate limit state of instability was considered, likely to occur in equilibrium configurations of reinforced concrete elements subjected to normal loads. Using the P-calc application, abacuses, and tables, columns with a cross-sectional area of 20x50 cm were simulated and calculated, with a service axial load of 3000 kN and a service bending moment of 90 kN·m, and characteristic compression strength of 50, 60, 70, 80, and 90 MPa. The design according to the new version of the standard showed a maximum increase for C80 concrete, being 2.68 times larger than the steel area calculated for the old version of the standard. For beam design, the UniCalcPro software was used with cross-sectional elements of 20x50 cm, considering a service bending moment of 70 kN·m, with the same strength classes as the columns. They showed a maximum increase in steel consumption for fck = 90 MPa, being 1.52% when comparing the 2023 version with the 2014 version of the standard.