Strength and deformation of confined high strength concrete

This paper presents the study on the strength and deformation behavior of confined high strength concrete. More than 100 actively confined high strength concrete specimens were tested under axial compression. The parameters of the study were concrete strengths and the magnitude of confining stresses applied to the specimens. From this study it was found that under increasing lateral confining stress, concrete experiences enhancement of strength and apparent ductility. The observed strength increase from the specimens is successfully modeled with the Mohr-Coulomb criterion, whereas the ductility increase is found to relate with the amount of strength increase. Based on the test results, a stress-strain model for confined high strength concrete is proposed. The stress-strain model is then used to simulate the behavior of reinforced high strength concrete columns. Comparisons of the simulated results with those from recently reported tests indicate good agreement.