Estudo comparativo entre a utilização de concreto leve e concreto convencional em elementos estruturais de um edifício multipavimentos.

Abstract

The use of concrete in constructions grows with the emergence of new materials along with technological advances that increase its range of uses. Among the types of this material, lightweight concrete has the advantage of having lower specific mass, presenting itself as an option in reinforced concrete structures. The study of the application of lightweight concrete is necessary, because despite its appearance in the last century, its use in buildings in Brazil is modest and its use may enable the reduction of loads on structural elements due to its lower specific weight, contributing to a reduction of the resistant elements and costs’ section. In this sense, the present work aims to make a comparative study of the use of lightweight concrete in the structure of a building in order to raise indicators that enable its use for this purpose. The comparative study was carried out through the processing of the structures in the AltoQi Eberick V10 software. Three structures were analyzed, one structure composed of conventional concrete (CC), one using lightweight concrete in the beams and slabs (CCL), and the last with lightweight concrete in the beams, slabs and pillars (CL). For the estimation of material properties, were used the specifications of NBR 6118 (ABNT, 2014) and EUROCODE 2 (2004). For dimensioning in ELU and ELS, the software was configured considering the criteria of NBR 6118 (ABNT, 2014). After the processing of the structures, the results showed that the use of lightweight concrete in the pillars contributed to the increase in horizontal displacements and instability of the structure. However, the displacements were within the limit imposed by the standard and the z range coefficient was within the limit of 1,10. So, the structures were classified as fixed nodes. The displacements in slabs and beams were always greater or equal in the structures containing lightweight concrete, and the structure with lightweight concrete also in the pillars obtained the largest displacements. However, the values are within the limits imposed by the standard. The effort in the beams were less for the use of lightweight concrete only in the beams and slabs, with a slight increase with the use of lightweight concrete also in the pillars. Finally, the use of lightweight concrete in the structural elements contributed to the reduction of the loads on the foundations and the consumption of steel in the structure. The reduction of input contributes to a reduction of the costs in the construction and and can make its use interesting.