Análise da influência da fibra de aço na resistência mecânica do concreto

Abstract

This experimental work investigates the effect of adding steel fibers on the mechanical properties of concrete mixed with different types and sizes of coarse aggregates. The methodology involved the preparation and testing of prismatic specimens (for flexural evaluation) and cylindrical specimens (for compressive strength control), based on ABNT standards, performing a comparative analysis between the concretes. Regarding the type, rolled pebbles and crushed stone were used. Regarding dimensions, rolled pebbles and crushed stone with a dmax of 12.5 mm were used. Three mix designs were evaluated: one reference design, i.e., without steel fiber, and two designs with different coarse aggregates, the focus of this study. The results indicated that the incorporation of steel fibers promoted significant increases in the toughness of the pieces, changing the behavior from brittle to ductile. Compressive strength showed less pronounced variations. Furthermore, it was observed that the type of aggregate influenced the mechanical performance, with crushed stone showing a higher peak strength than the concrete mixed with rolled pebbles.