Análise comparativa do comportamento estrutural e desempenho construtivo de lajes lisas maciças em concreto armado versus concreto protendido – estudo de caso aplicado em TQS

Abstract

In the last decades great innovation in the constructive processes has been observed, however, in Brazil still prevails, for cultural reasons, the use in residential buildings of conventional structure: beams, slabs and pillars. Among these innovations and as a means of rationalizing the execution of the structures, solid flat plates have advantages mainly because they do not require beams for the redistribution of loads. In specific situations where solid flat plates are applied in Brazilian buildings, they usually do with the use of prestressing. This often increases the value of its execution, which together with its greater technical specificity discourages new initiatives with this technology. The application of solid flat plates to reinforced concrete can be a viable alternative to stimulate the use of this constructive process in the country, as long as its potentialities and limitations are known. This work consists of a case study applied in the TQS software, with a comparative approach in which the analysis of the structural behavior and constructive performance of reinforced solid flat plates and prestressed solid flat plates, both applied in the same residential building architectural project, is carried out. The purpose of this research is, among others, to demystify the idea of inefficiency of the use of reinforced solid flat plates, demonstrating their points of convergence and divergence in relation to the prestressed solid flat plates. The prestressed structure consists predominantly of 12.7 mm low relaxation grease monocordels (CP-190 RB) and the reinforced structure composed of CA-50 steel in various diameters, both of which are used as C35 concrete. In the study, an architectural project was selected and its structure was launched through the computational program for both typologies, dimensioning and detailing them, in order to, through modeling, obtain their requesting efforts and analysis of global stability, following the requirements of NBR 6118:2014 - Concrete Structures Project -Procedure. As a result, in addition to proving the easibility and competitiveness of the solid flat plate in reinforced concrete, which for this case study presented savings of around 10% in relation to prestressed concrete, it is also possible to measure several comparative indices and relations between the typologies.