Modelling eccentrically loaded high-strength concrete columns

Based on a confined concrete model for concentric static loading, an analytical method is proposed to predict the behaviour of laterally confined concrete columns subjected to eccentric static loading. Theoretical predictions are verified against the experimental studies reported in the literature. Normal, medium and high-strength concrete were used. Although much research has been reported in the literature concerning eccentric loading of confined concrete columns, there exists a controversial issue about the effect of strain gradient. This method fully incorporates the effect of strain gradient on the lateral confining pressure exerted by transverse reinforcement. It includes modifications for coefficient of effectiveness, and the fact that cover concrete continues to carry load even after spalling. By incorporating the variables, which affect the moment curvature behaviour of laterally confined eccentrically loaded columns, the analytical procedure described here gives a superior alternative to use of a different stress-block for concrete under a strain gradient.