Modeling of Stress-Strain Relationship and Deformability for Confined High-Strength Concrete

Some of the most widely referenced models for stress-strain relationship of confined concrete columns with square cross section are reviewed, and the performance under monotonic compressive loading is evaluated based on a database in which compressive strength ranges from 40 to 140 MPa and yield strength of transverse reinforcement ranges from 400 to 1400 MPa. It is found that the majority of the models examined can predict the strength of confined concrete reasonably well, however, the predictability to the deformation is rather low. A model for predicting deformability of confined concrete column subjected to monotonic compressive loading is proposed in terms of strain energy provided by confining reinforcement up to the peak point and the point of 85% of the maximum stress beyond the peak point. Predictions based on the strain energy are found to be in good agreement with experimental results.