Title: Effect of Steel Fiber Reinforcement on Fresh Mix Properties of Concrete

Author(s): M. Ziad Bayasi and Parviz Soroushian

Publication: Materials Journal

Volume: 89

Issue: 4

Appears on pages(s): 369-374

Keywords: air; concretes; fibers; mixing; slump tests; workability.

DOI: 10.14359/9751

Date: 7/1/1992

Abstract:
An experimental study on the effects of fiber reinforcement index of different steel fiber types on fresh mix properties of fiber concrete is reported. The fiber types considered in this study are straight-round, crimped-round, crimped-rectangular, hooked, and hooked-collated. Different lengths and volume fractions of fibers are investigated. The fresh fibrous mixes are characterized by their slump, inverted slump cone and Vebe times, subjective workability measurement, and air content. The workability of fresh fibrous mixes is found to be damaged by increasing fiber reinforcement index at a comparable rate for different fiber types. At a specific fiber reinforcement index, however, crimped fibers produce concretes with higher slumps, and straight fibers generate mixtures with lower inverted slump cone times compared to the other fiber types of this study. By decreasing fiber length and, consequently, increasing the number of fibers, entrapped air content tends to increase in the mix. Also, deformed (crimped or hooked) fibers have a tendency to entrap more air in the fibrous mix compared to straight-round fibers at the same reinforcement condi-tion.