Title: Influence of Concrete and Fiber Characteristics on Behavior of Steel Fiber Reinforced Concrete under Direct Shear

Author(s): Ali R. Khaloo and Nakseok Kim

Publication: Materials Journal

Volume: 94

Issue: 6

Appears on pages(s): 592-601

Keywords: compressive strength; concretes; ductility; fibers; tests; reinforced concrete; shear properties; specimens

DOI: 10.14359/344

Date: 11/1/1997

Abstract:
Results of an experimental investigation carried out to assess the effect of various concrete strength levels on strength and ductility behavior of steel fiber reinforced concrete (SFRC) under direct shear is reported. The principal variables of the testing program were: (a) compressive strength of concrete, (b) V. of steel fibers, and _ the aspect ratio of steel fibers. The concrete strengths investigated include 28 MPa for low strength (LC), 44 MPa for normal strength (NC), 54 MPa for medium strength (MC), and 72 MPa representing high strength concrete (HC). Fiber content ranges from zero to 1.5 percent by V. of matrix. In total, twenty-eight push-off type specimens were tested. Formulations are proposed to predict the shear response of the test specimens. Addition of fibers regardless of concrete strength led to shear strength, ductility, and toughness enhancement of SFRC; however, the improvement for higher strength concrete was more pronounced than that for lower strength concrete. This is attributed to the improved bond characteristics associated with the use of fibers in conjunction with high strength concrete. Fibers with larger aspect ratio provided higher toughness and higher ultimate shear strength concrete. The influence of fiber V. on shear behavior of concrete was much higher for high-strength concrete. In general, good agreement between the shear behavior predictions and the test results was found.