Study on stress-strain relationship of high-strength concrete confined with high-strength stirrups under axial compression.

In order to investigate the compressive behavior of high-strength concrete confined with high-strength stirrups, high-strength concrete prism specimens confined with high-strength stirrups were tested under axial compression. The effects of three variables such as stirrup ratio, stirrup yield strength and stirrup configuration were analyzed. It is shown that high-strength stirrups do not yield at peak stress of confined concrete. The calculation method for effective lateral stress and actual stirrups stress were suggested based on the stress mechanism. The high strength stirrups can provide more effective lateral stress after the peak stress, which makes the descending section more gentle for stress-strain curve of confined concrete. Based on test results and theoretical analysis, the equations for calculating the strength and strain of confined high-strength concrete were proposed, the formula of stress-strain curve were suggested. It is shown that the theoretical stress-strain curves are in good agreement with the experimental curves. [ABSTRACT FROM AUTHOR]