A compact analytical material model for unconfined concrete under uni-axial compression

The majority of the published material models for unconfined concrete under uni-axial compression consist of two branches. The recent trend is to introduce empirical modification factors in the existing material models to improve agreement between experimental and analytical results, particularly for High Strength Concrete. This paper presents a compact analytical material model in which the available conditions uniquely determine all the model parameters. It consists of a single branch and the need for empirical factors is eliminated. An application of this material model to published experimental data on normal and lightweight concretes over a wide strength range demonstrates its versatility. The agreement between experimental and analytical results is as good as that which may be provided by any other existing model. The rationality and elimination of empiricism are additional gains.