Title: Constitutive Laws of Softened Concrete in Biaxial Tension Compression

Author(s): Abdeldjelil Belarbi and Thomas T. C. Hsu

Publication: Structural Journal

Volume: 92

Issue: 5

Appears on pages(s): 562-573

Keywords: biaxial loads; compatibility methods; compression; cracking (fracturing); equilibrium; reinforced concrete (strains); stresses; structural members; Structural Research

DOI: 10.14359/907

Date: 11/1/1995

Abstract:
A softened truss model was developed during the past decade at the University of Houston for predicting the behavior of reinforced concrete subjected to shear and torsion. The model, based on the conditions of equilibrium and compatibility, utilizes realistic constitutive laws for concrete and reinforcement. The required constitutive laws for concrete and reinforcement were studied by testing 22 full-size reinforced concrete panels. These large test panels were subjected to tension in one direction and compression in the perpendicular direction, using the universal panel tester at the University of Houston. Test results revealed that the strength and stiffness of concrete in compression were softened primarily by the presence of tensile strains in the perpendicular direction. The effect of other parameters, e.g., load path, percentage of steel, and spacing of reinforcing bars, was evaluated. Based on these tests, improved softened stress-strain relationships of concrete in compression were developed.