Análise comparativa do dimensionamento de vigas com a utilização das normas ABNT NBR 6118:2014 e o ACI 318-19

Abstract

There are several ways to determine the shear strength in reinforced concrete beams, such as through the modified compression field theory proposed by Bentz and Vecchio (1986), the struts and ties model and the classic and generalized truss both proposed by Ritter (1899) and Mörsch (1909), among others. In the present work, a reinforced concrete beam was selected, where its transverse reinforcement is dimensioned according to the two calculation models of ABNT NBR 6118:2014 and also through the two calculation methods of ACI 318-19. These standards differ in the way the concrete contribution is determined, but both are based on the truss model by Ritter (1899) and Mörsch (1909). The dimensioning is carried out using the loads made available through ABNT NBR 6120: 2019; the combination of loads, reinforcement ratios and spacings were calculated at the discretion of each standard, in addition to the fact that the study will rely on the aid of the Ftool (2017) software to obtain the requests and Microsoft Excel (2018) for the calculation worksheets. Tables and figures are presented with the results obtained to carry out the analysis of the results and establish the factors that influenced the sizing. Through a statistical analysis, it was verified that the comparison between the sizing through the calculation model I of the ABNT and the simple model of the ACI presented a little dispersed and symmetrical result, already in the other comparisons there was considerable dispersion and asymmetry, however in the confrontation between the ABNT model II and the detailed method of the ACI there was symmetry. Overall, design according to ACI provided higher steel consumption.