Specified Domain in N_u-M_u Interaction Diagram for Logical Judgment in Numerical Analysis on Compression Reinforced Concrete Members

Abstract

A series of specified domains in N_u-M_u interaction diagram are proposed to determine optimal reinforcement schemes for rectangular RC column sections subjected to uniaxial eccentric load. These domains divide the area covered by interaction diagram into four regions of safety zone, compression-controlled zone, balanced failure zone and tensioncontrolled zone, which can help engineer to understand all possibilities of section failure under varied reinforcement scheme when they carried out a section design for columns with numerical analysis. With the physical information included in the diagram, the domains help to establish logical judgment between practical reinforcement schemes specified by the Chinese code (GB50010-2010) and corresponding load combination (N_u, M_u) in interaction diagram, and also provide physical interpretation on any calculated result of steel consumption.