Shear strength of members without transverse reinforcement

Abstract

The variable angle truss model is extended to members without transverse reinforcement by introducing concrete tension ties perpendicular to concrete compression struts. The modified compression field theory approach of limiting the shear transfer across diagonal cracks is combined with the variable angle truss model to develop equations for the shear capacity of members without transverse reinforcement. These equations are the theoretical basis of tabulated values for members without stirrups in the general shear design method of the 1994 Canadian concrete code. This paper also presents the results from an experimental study in which 27 narrow (beam-like) wall elements, with significant longitudinal reinforcement and little or no transverse reinforcement, were subjected to combined axial tension, bending moment, and shear. The experimental results are compared with predictions from the 1994 Canadian concrete code, as well as the American Concrete Institute building code. Key words: building codes, reinforced concrete, shear strength, structural design, tension, tests, truss model.