Lajes nervuradas moldadas in loco e pré-moldadas unidirecionais: projeto, dimensionamento e detalhamento

Abstract

Ribbed slabs of reinforced concrete are the set of beams that are sympathetic through a concrete table. There are several possibilities of execution for such slabs, finding themselves from pre to molded in loco. In the case of pre the concrete cover is still molded in the spot being only the girder (rail or truss) pre shaped. The calculation of ribbed slabs has the same principle as calculating massive slabs, presenting, however additional details that cannot be verified. It is necessary to have a good understanding of the correct calculation process in order to ensure the perfect functionality of the ribbed slab, considering values in sizing and efforts that correspond to the actual requests encountered when working. Sizing follows security and economics precepts making this type of slab attractive, currently, on the market. This work will make relevant observations on the calculation methods in order to settle any trace of doubts regarding the process and the functionality of the slabs. All observations will be based on recommended bibliographies and safe sources, always seeking the simplicity and convenience of explanations. A good theoretical and technical framework will be developed in depth, where the methods and procedures of calculation are deepened, examples of the most frequent types of ribbed slabs found in the market, sizing them and detailing them. The standards and procedures used shall be referenced based on the recommended bibliography. The main types of ribbed slabs to be calculated, scaled and detailed are shaped ribbed slabs in loco and ribbed slabs type rail. These are the most frequent types of slabs found in the Brazilian market. The analysis will be given with the armed slabs in one direction, and will use the aid of tables and graphs that facilitate the development of the structural calculation.