Resumen de Analysis of the resistance to fire of solid concrete boards with polypropylene microfibers and long curing time
Gustavo Manica, Fabricio Bolina
Reinforced concrete elements with long curing ages tendnotto present spallingwhen subjected to high temperatures sinceheat transfer in concrete is influenced mostly by the materials constituting its composition. Polypropylene microfiber-reinforced concrete presents more porosity and higher thermal insulation as the fibers melt when exposed to high temperatures. Therefore, this study aimed to assess the influence of the addition of polypropylene microfibers on the resistance to fire of reinforced concrete boards. The mechanical tests required crafting18 boards and 3 walls in real scale, which measured 3.15x3.00m. The analysis comprised 3 types of systems, being the reference reinforced concreteandthe concreteswithpolypropylene microfiberratiosof 0.97kg/m³ and 1.94kg/m³. Were extract 18 specimens for the axial compression test. The fire test was performed in a vertical furnace under the ISO 834 curve. None of the 3 walls displayed spalling and the boards with higher microfiber ratios presented better fire performance, withsmaller maximum displacements. The wall with 1.94kg/m³ microfiber ratio obtaineda gain of 23.5 min in thermal insulation compared to the reference reinforced concrete wall.It was also perceived that the incorporation of polypropylene microfibers in theconcrete reduces its compressive strength.
