Title: Compressive Force Path Concept: Basis for Reinforced Concrete Ultimate Limit State Design

Author(s): Michael D. Kotsovos

Publication: Structural Journal

Volume: 85

Issue: 1

Appears on pages(s): 68-75

Keywords: aggregate interlock; beams (supports); compressive strength; limit state design; loads (forces); reinforced concrete; structural design; tensile stress; triaxial stresses; trusses; Structural Research

DOI: 10.14359/2986

Date: 1/1/1988

Abstract:
An experimental investigation of the behavior of reinforced concrete beams with various arrangements of stirrups has indicated that such concepts as shear capacity of critical sections, aggregate interlock, truss analogy, and others, forming the basis of current ACI code provisions for shear design, are in conflict with the observed structural behavior. It is shown that the causes of beam failure are associated with the development of tensile stresses in the region of the path along which the compressive force is transmitted to the supports and not, as is widely considered, the stress conditions in the region below the neutral axis. This conclusion has led to the formulation of the compressive force path concept, and it is argued that this may form a suitable basis for the development of simple and rational design methods.