Estudo experimental de placas pré-moldadas de concreto com fibras de aço

Abstract

This study presents an experimental investigation on the mechanical behavior of precast concrete slabs reinforced with steel fibers (SFRC). The objective of this research was to analyze the influence of different types and dosages of steel fibers on the flexural tensile strength of these slabs. Accordingly, 21 slabs were cast using variations of Wiremix W40, Dramix 3D 45/50 BN, and Dramix 3D 65/60 BG fibers at dosages of 1.0% and 1.5%. The tests were conducted in accordance with NBR 12142 (ABNT, 2010), employing the four-point bending method. The results demonstrated that the addition of fibers significantly improved the mechanical strength and ductility of the slabs, reducing the inherent brittleness of conventional concrete. From an economic perspective, a 1.0% dosage for Fiber Types 2 and 3 proved to be more advantageous, as increasing it to 1.5% did not result in significant strength gains or notable differences regarding fiber type. Furthermore, it was identified that both fiber dosage and type directly influence material performance, highlighting the importance of proper dosage selection for structural applications.