The flexural stress-strain relationship of concrete confined by rectangular transverse reinforcement

Summary To understand the plastic deformation capacity of critical regions reinforced with longitudinal and transverse reinforcement, it was felt that the stress-strain relationship of bound concrete in flexure must first be established. Sixteen specimens were tested in a specially constructed testing frame under the action of a major and a minor load. The stress-strain relationship for the concrete was obtained by an approach similar to that used by Hognestad, Hanson and McHenry in conjunction with a special graphical interpolation technique. A generalized relationship was finally developed expressed as a function of: the spacing of binders; the ratio of the bound area to the total area under compression; the size of the binders; and the shape of the concrete cross-section.