Evaluation of the impact of two types of steel fibers (SE), mono and 3D, on concrete properties, when added isolated or blended

A L Bauer,H Ehrenbring,U C M Quinino,D Schneider,B Tutikian

doi:10.1590/s1983-41952020000300002

A L Bauer, H Ehrenbring + Show 3 more

Open Access

https://doi.org/10.1590/s1983-41952020000300002

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Abstract

Abstract The brittle behavior of concrete can be compensated by the addition of reinforcements, providing benefits such as improved crack control, residual strength and increased flexural strength. It is usual to apply mono fibers to concrete, but their positioning in the matrix may not be homogeneous, consequently increasing the susceptibility to fracture planes with fewer reinforcements. This study aimed to evaluate the use and behavior of simple (mono) and space (3D) steel fibers (SE), in order to achieve a more homogeneous mixture, increase the effectiveness of fibers in restricting cracks and improve mechanical properties. The fresh-state was assessed through slump and VeBe tests, whereas the hardened-state tests comprised axial compressive strength, flexural strength and the flexural toughness factor. The volume content of simple and space fibers varied from 0 to 0.93%. Based on the results, it can be stated that space and simple fiber contents improved rheological and mechanical properties of the composite in isolated (0.29%) and hybrid (0.64%) combinations, since their overall performance exceeded the other mixtures’. However, space fibers caused considerable workability losses compared to the conventional concrete, hindering its casting and harming its hardened-state properties.

Highlights

Concrete is a material with sensitive behavior that relies on other components that can change its failure mode [1]
Even if the identified results are interesting, there is still a gap concerning the performance of concrete reinforced with space fibers, which are marked by a specific setting that is structured with simple fibers acting in 3 directions (3D)
Velasco [35] stated that fiber-reinforced concrete tends to lose workability and fluidity, a loss that becomes clearer as fiber content increases

Summary

Introduction

Concrete is a material with sensitive behavior that relies on other components that can change its failure mode [1]. Studies on the use of 2D fibers were developed as well, exemplified by the textile-reinforced concrete [12, 13], which brings along a series of advantages compared to conventional and reinforced concretes Some of these advantages are great tensile and compressive performances, high durability, owing to the matrix having low water-cement ratio (

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