Title: Compression Sress-Strain Curve for Design of Reinforced Concrete Beams
Author(s): Arne Hillerborg
Publication: Symposium Paper
Appears on pages(s): 281-294
Keywords: beams (supports); bending; compression; concretes; dimensional analysis; ductility; fracture properties; moment-curvature relationship; reinforced concrete; stress-strain relationships; structural design; Structural Research
The stress-deformation relation now generally accepted for tensile fracture, i.e., with the descending branch described by means of a stress-displacement relation in a localized band, has been applied to the compressive stresses in a bent, reinforced beam. The displacement in this band is averaged over a length, which is proportional to the depth of the compression zone. The resulting average stress-strain relation, which is strongly size-dependent, is used for the analyses of the stresses in a rectangular beam section, and for the corresponding moment-curvature relationship. The results differ appreciably from those from conventional assumptions. The new approach shows a better agreement with test results than the conventional approach. Further test comparisons are, however, recommended. The new approach may form the basis of changed design assumptions, particularly for high-strength concrete.