Title: Bond-Slip Mechanisms of Steel Fibers in Concrete

Author(s): A. E. Naaman and H. Najm

Publication: Materials Journal

Volume: 88

Issue: 2

Appears on pages(s): 135-145

Keywords: bond (concrete to reinforcement); bonding; bond stress; fly ash; fiber reinforced concrete; latex (plastic); metal fibers; microsilica; pullout tests; reinforcing steels; slippage; Materials Research

DOI: 10.14359/1896

Date: 3/1/1991

Abstract:
A comprehensive experimental program on pullout and pullthrough tests of steel fibers from a cement-based matrix is described. Emphasis is placed on the accurate measurements of the pullout load versus end-slip response. Parameters included three different types of fibers (smooth, deformed, and hooked); three different mortar matrixes with low, medium, and high strengths; one cement-based slurry matrix; and additives such as latex, fly ash, and microsilica. The media from which the fibers were pulled out included a control mortar mix without fibers, mortar mixes with 1, 2, and 3 percent fibers by volume, and a SIFCON matrix containing about 11 percent fibers by volume. For smooth fibers, five different diameters and three different embedment lengths were investigated. Experimental pullout load-versus-slip curves are needed to derive typical bond shear stress-versus-slip curves considered to be a property of the interface.