Comparative study of confinement models for high-strength concrete columns

Abstract

The analysis of structural members requires an analytical model for the full stress-strain relationship of concrete in compression both in confined and unconfined states. Many empirical confinement models have been reported in the literature during the last three decades. The models developed for normal strength concrete are not applicable to high-strength concrete, because they overestimate the ductility of high-strength concrete. This paper critically reviews the various proposed stress-strain models for confined high-strength concrete columns. There are very few models for confined concrete with compressive strength in the range of 60–120 MPa. The main objective of the present study is to examine the capabilities of the various models to predict the actual experimental behaviour of confined concrete columns with concrete strengths falling in this range. To this end, twenty-two test specimens were chosen from the reported experimental studies in the literature and their stress-strain curves were compared with the ones predicted by the various models. It was shown that the Legeron and Paultre model estimates the actual practical curves more closely in comparison with other models employed in this study.