Análise da influência de adição de fibras de aço como reforço primário no concreto

Abstract

Concrete as the most popular material in the civil construction sector has been going through the process of combination with addition in its matrix, in which it changes the behavior of its properties in order to achieve a gain in mechanical performance. The objective of this work was to analyze the influence of the incorporation of steel fibers in the composition of plain concrete, regarding workability, tensile strength and failure mode. The contents of steel fibers incorporated in the concrete composition were 5%, 10%, 20% and 30% in relation to the cement mass, for concretes of classes C15, C20 and C30. Behavioral variations for each fiber content are noticeable; classes C15 and C20 had an increase in indirect tensile strength with up to 20% of fiber incorporation, declining to levels of 30%, class C30 obtained increases in increasing mechanical performance for all percentages. The workability of Steel Fiber Reinforced Concrete (CRFA) decreases with the increase of fibers, in all strength classes analyzed. In all cores there was a reduction in crack propagation and an increase in the capacity of absorption and redistribution of efforts, changing the behavior that was fragile before the addition to a pseudo-ductile performance.