Title: Reinforcement Buckling in Reinforced Concrete Flexural Members
Author(s): Charles F. Scribner
Publication: Journal Proceedings
Appears on pages(s): 966-973
Keywords: beams (supports); buckling; cantilever beams; cyclic loads; earthquake-resistant structures; flexural strength; reinforced concrete; reinforcing steels; stiffness; structural analysis; structural design; stirrups; ties (reinforcement).
The relationship of the flexural stiffness of a confining tie to the inelastic buckling of longitudinal reinforcement in a beam subject to repeated reversed inelastic flexure is discussed. A theoretical analysis of the problem indicates that buckling of longitudinal bars can be influenced by confining tie size and spacing. Tests of six cantilever beams demonstrate that large ties can prevent some types of longitudinal bar buckling in which the buckled length of the bar spans more than one tie spacing interval. However, even large, closely spaced ties provided no guarantee against buckling of reinforcement in a beam subjected to very large flexural displacements. Recommendations for design are given based on results of analysis and on behavior of the specimens tested.