Análise paramétrica do comportamento termomecânico de lajes de concreto armado com diferentes agregados expostas ao fogo (Parametric analysis of thermomechanical behavior of reinforced concrete slabs with different aggregates in fire)

Reinforced concrete structures, when subjected to fire, have their mechanical resistance reduced related to the behavioral change of the material. Many experimental and numerical research on the behavior of concrete exposed to fire have been carried out on beams and columns, with slabs being studied less frequently, mainly due to its size and consequently higher research costs. This paper carried out a numerical analysis of the thermomechanical behavior of reinforced concrete slabs exposed to fire, using finite element modeling. The parametric analysis carried out changing the aggregate type of concrete showed that when exposed to ISO834 fire curve, the displacement in the center of slab with siliceous aggregate was 47% higher than the slab with calcareous aggregate. Analyzing the crack opening, for slabs exposed to ISO834 fire curve, the first 1mm-cracks were noticed at 18min when using calcareous aggregate, while the slabs with siliceous aggregate started at 13min.