Análise da influência da variação de temperatura e retração em edifícios de concreto armado sem juntas

Abstract

This work presents an analysis on the inclusion of the effects of temperature variation and shrinkage in reinforced concrete buildings without joints, evaluating the influence: on the resulting efforts, on the stability and on the dimensioning of the structure. According to ABNT NBR 6118:2014, the effects of uniform imposed deformations on parts must be checked, however the standard does not specify clear criteria for the use of joints, it only clarifies that the effects of imposed deformations can be minimized by creating joints, so it concludes It is understood that the decision and the parameters to carry out the choice of adopting joints in your project would be at the discretion of the structural engineer. In this study, six reinforced concrete buildings with lengths of 30, 45 and 60 meters were developed. The program for the design of concrete structures, Eberick 2022 (AltoQi, 2022), was used to dimension buildings with the application of the effects of temperature variation and shrinkage and without these effects, the buildings received the name of reference and experimental building, respectively. First, a reference building was dimensioned for each length, right after this step, the same structural design was used and the effects of temperature variation and shrinkage were added to its structure, in this way the experimental buildings were created. The results of these 6 buildings were collected and the changes that were necessary to reach the final design of the structures were analyzed. The greatest consequence of considering these effects is the increase in the displacements that are essential in the verification of the ELS, in the beams the increase in the maximum deflection was up to 193%. It is concluded that the length of the building, when uniform imposed deformations are applied, directly affects the magnitude of the axial forces and, therefore, the consumption of steel in the structure, which increased by up to 18% in the case of greater length.