Title: Direct Tension Tests of Concrete Reinforced with Hooked Steel Fibers

Author(s): Julian Carrillo, José A. Pincheira, Joaquín Abellán-García

Publication: Materials Journal

Volume: 119

Issue: 6

Appears on pages(s): 77-89

Keywords: direct tension test; dog-bone test; fiber-reinforced concrete (FRC); hooked-end fibers; indirect flexural test; residual strength

DOI: 10.14359/51737186

Date: 11/1/2022

Abstract:
Studies have shown that steel fibers with hooks can significantly improve the response of steel fiber-reinforced concrete (SFRC) in tension. While direct tension tests allow measurement of the true tensile strength, they can be considerably more difficult to perform. In this study, direct tension tests of dog-bone-shaped specimens and flexural strength tests were conducted to measure and compare the response of SFRC containing fibers with single, one and a half, or double hooks at the ends. Fiber dosages of 20, 40, and 60 kg/m3 were investigated. The results from direct tension tests of specimens with fibers having double hooks exhibited post-cracking peak tensile strengths up to four times higher than those of specimens with fibers with a single hook at the ends, and as much as 67% more than those measured from specimens with fibers having one and a half hooks. Based on the results of this study, a simple model to correlate the results obtained from the flexural strength and direct tension tests is proposed.