Slender high-strength concrete columns subjected to eccentric loading

An experimental study of the behavior of reinforced concrete columns and results of a nonlinear finite-element analysis are presented. Twelve full-scale columns with square sections were tested under eccentric monotonic loading. Effects of key parameters such as concrete strength, stirrup spacing, slenderness of the columns, and eccentricity of the applied axial load were studied. Significant gains in load capacity were obtained with increased concrete strength. The results of the finite-element analysis correlate well with the results of the tests. A parametric study was made to examine the difference in failure modes for the different concrete strengths, length-to-width ratios, and loading eccentricities. The higher compressive concrete strength was especially advantageous when the load eccentricity was small. When the eccentricity was increased, the strength of the high-strength concrete columns decreased more rapidly than that of the normal-strength columns. However, the high-strength concrete columns still exhibited a greater load capacity than the normal-strength columns.