Experimental studies on axial load performance of high-strength concrete short columns

Abstract

This paper presents the results of an experimental investigation into the axial load performance of steel-reinforced high-strength concrete short columns. The performance of a total of ten specimens is investigated, including the failure pattern, load–strain response, compressive strength and ductility. The parameters considered in this study are stirrup and structural steel arrangements. The definition of effective strength is developed to measure the compressive strength of columns due to the sudden drop of strength at peak. The ductility of columns is characterised by the ratio of after-peak and before-peak area under the curve of the axial load plotted against axial strain. Based on the experimental research, it is found that stirrups affect ductility and residual strength of columns, but not the peak strength. Structural steel influences the peak and residual strength and ductility of columns. Ductility of columns is approximately proportional to the effective confinement index if stirrups yield after peak. The effect of structural steel on ductility is more obvious when the effective confinement index is larger.