Análise dos domínios de deformação de seções retangulares de concreto armado submetidas à flexão composta normal – segundo NBR 6118/14

Abstract

In order to follow the development occurred in the field of concrete technology, which has permitted the achievement of concrete with increased resistance, brazilian norms ABNT NBR 6118:2014 has incorporated in the latest version in force just over a year, considerations about the concrete of strength classes higher à − 50 limitados à classe − 90. These concretes are more fragile and the constitutive relations for those used to the − 50 class had to be modified to take into account this fact. Taken as fixed parameters to calculate the resistance calculation requests, such as the last bending deformation of concrete, become dependent on its characteristic resistance. This makes the wording used for the design of reinforced concrete sections subject to normal effort and bending moment has to be updated. In this work were developed tables for sizing the flexo - traction and flexo- compression rods and sections of reinforced concrete columns, in accordance with the latest version of NBR 6118. We present the expressions and procedures employed in generating these tables, taking into account the concrete to − 90. It indicates the procedure used to obtain the requests pillars, with which it comes to dimensioning. Classes of − 20 to − 50 the tables are unique to all intermediate classes. − 55 à − 90, each class corresponds to a table. Four arrangements of reinforced were used, and considered three departures from the armor of concrete edge. Are examples of application of the tables. The results were consistent with what was developed.