Bond-Slip Mechanisms of Steel Fibers in Concrete

A comprehensive experimental program on pullout and pullthorugh 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 3 different type of fibers, 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 medium from which the fiber was pulled out included a control mortar mix without fibers, mortar mixes with 1, 2, and 3 % fibers by volume, and a SIFCON matrix containing about 11 % fibers by volume. For smooth fibers, 5 different diameters and 3 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.