Behavior and ductility of reinforced concrete short columns using global truss model

Abstract

The main results of an experimental program on eight full-scale reinforced concrete short columns are presented. The specimens were subjected to compression and cyclic reversed uniaxial shear displacements. The parameters investigated were the value of shear ratio, the ratios of longitudinal and transverse reinforcement, and the normalized axial force ratio. Two different layouts of main reinforcement were tested: conventional (longitudinal) and a combination of longitudinal and bidiagonal reinforcement. Columns with shear ratio equal to I were shown to behave in a particularly brittle manner The presence of bidiagonal reinforcement improved to some extent the ductility of the specimens, but not to the level required by current aseismic design. The relative performance of the specimens tested is evaluated according to various ductility criteria. A model for designing short columns is also presented.