Análise das ações de temperatura e retração do concreto em lajes de cobertura em uma edificação de concreto armado no município de Santa Maria-RS

Abstract

This work presents the analysis of the effects imposed by temperature variations, linear gradient and retraction in the covering slab of a building, using temperature data obtained in the city of Santa Maria/RS. Permanent and accidental loads were also considered, following the specifications of NBR 6120 (ABNT, 2019), with this, it was created the combinations presented in NBR 6118 (ABNT, 2014). The building has a conventional reinforced concrete structure with masonry sealing walls, consisting of four floors (ground floor and three floors), with a generic geometry. The analysis of the slab was developed through modeling made in the SAP 2000 software, which enabled verifications and comparisons between different models for the ELU and ELS. Two models were developed in the software, both containing bar elements for beams and pillars, and shell elements for slabs, all of them made of reinforced concrete. Thus, for the analyzed models, the values of bending moments were compared with the covering slab that presented the highest stress concentration. In addition, the steel areas were verified for each of the calculated bending moments. Finally, crack and vertical displacements opening were checked, based on the standard limits. Therefore, it can be demonstrated that the effects caused by linear gradient temperature loads and retraction generate significant increases in the stresses suffered in the roof slab, highlighting the importance of not neglecting such loads, since these actions can lead to serious pathological problems for structural and sealing elements.