Verificação da conformidade da taxa de armadura de pilar pré-moldado: estudo de caso para um galpão em estrutura mista

Abstract

This research presents a panoramic approach of precast structures for sheds. These buildings have been emphasized as the most common destination of precast concrete in Brazil, as seen by the amount of constructions in progress. This study proposed to present the challenges faced by many building companies in the last two years, caused by the sanitary crisis scenario. The effects were noticed by the steel price rises and the lack of raw material on the national market. Therefore, the study goals were to estimate the conformity of the steel rate for a precast column based on a reference project by a company in midwest Brazil, and also based on the brazilian standards ABNT NBR 6118:2014 and ABNT NBR 9062:2017. For this purpose, the design of the structural element for a shed was studied under two considerations about the actions in precast concrete structures, performed in the free softwares Visual Ventos and Ftool. The first consideration was a case of oblique compression on the column, while the second case was traction. The results were compared with the ones originally practiced on the company, and the new steel rates were analyzed. The steel rate obtained on a section of the column for a traction case were 17,5 cm², wich is higher than the original project (10,0 cm²), with major consume of longitudinal armor in the new project. It shows that, for structural safety, the reduction of the steel rate is not viable in sheds submited to large wind actions.