Title: Shear Friction Tests with High-Strength Concrete

Author(s): Lawrence F. Kahn and Andrew D. Mitchell

Publication: Structural Journal

Volume: 99

Issue: 1

Appears on pages(s): 98-103

Keywords: high-strength concrete; shear; test.

DOI: 10.14359/11040

Date: 1/1/2002

Abstract:
This experimental study showed that the current ACI shear friction concept can be extended to high-strength concrete. Fifty pushoff specimens were tested with uncracked, precracked, and cold-joint interfaces. These specimens mimicked those used by previous researchers in the development of shear friction. Concrete strengths varied from 6800 to 17,900 psi (46.9 to 123.4 MPa), with transverse reinforcing ratios between 0.37 and 1.47%. An equation is proposed that more accurately predicts the shear friction strength of cold-joint and uncracked interfaces for high-strength concrete. It is recommended that the current upper shear stress limit of 0.2fc¢ be retained but that the 800 psi (5.5 MPa) shear stress limit be eliminated.