Single-span, Continuous and Slender Deep Beams Made of High Strength Concrete

Abstract

The current design recommendations for concrete deep beams given in the ACI Code, Canadian Code, CEB-FIP Model Code, CIRIA Guide-2, etc., are based on research results on normal strength concrete. As such, these design recommendations may not be directly applicable to deep beams made of high-strength concrete. A summary of the authors' recent research on the shear behavior of deep beams made of high-strength concrete is presented. Experimental results on the ultimate shear strengths of single-span, continuous, and slender deep beams as affected by the strength of concrete, shear-span-to-depth ratio, and slenderness ratio, are compared to various design methods. It is found that the ACI method is overly conservative for all cases, the Canadian Code method is unconservative for higher strength concrete, the CEB-FIP method gives somewhat scattered predictions, and the CIRIA Guide-2 is slightly unconservative for all cases. A minor modification on the CIRIA Guide-2 method is shown to yield a reliable method for all the cases investigated.