Dimensionamento de um pavimento misto aço-concreto com aberturas na alma das vigas

Abstract

This study presents the design of a steel-concrete composite floor with beams with holes in the web. The work starts from a bibliographic review that introduces the elements of a composite floor, highlighting its constructive aspects, structural behavior, and design rules, according to the Brazilian Standard NBR 8800:2008. The review is limited to a shored structure, aiming the lowest possible heights for both slabs and beams. Based on a simplified building, the slabs were defined as simply supported one-way slabs, and their final heights were 100 mm for the roof floor and 120 mm for the typical floors, with a difference caused by the live loads. The beams were separated into five types of loading – G1, G2, G3, G4 and G5 – with variations for the typical floor and roof floor, totaling ten variations. The beams are dimensioned, emphasizing the step-by-step procedure for the G5 beams, which are the most loaded, so that this document serves as a theoretical reference in the future. Finally, the detailing of the holes is done for G2, G3 and G5 beam types from the typical floor in two different situations and comparing circular, square, and rectangular hole shapes. In general, the conditioning factors for the design process were the span size and the vertical displacement limits. In addition, circular holes have an advantage when compared to other shapes because they do not require additional shear connectors.