Prediction of stress-strain behavior of spirally confined concrete considering lateral expansion

This paper proposes a new analytical model for the relationship between the axial and transverse strains of confined concrete in uniaxial compression. The proposed model was developed based on empirical data for a circular section confined by spirals. A column with a circular section and subjected to uniaxial compression was considered. The proposed model predicts the stress in the transverse confinement reinforcement to estimate the relationship between the axial strain of the column and tensile strain of the transverse confinement reinforcement. The model can also produce the axial stress-strain relationship of the confined concrete of the column. The predicted axial and transverse strains of the confined concrete section corresponded to the observed axial peak stress of a column evaluated in previous research with good accuracy. This model will be an effective tool for investigating the effect of circular spirals on the structural behavior of confined concrete and enhancing the accuracy of structural behavior analysis for a column under uniaxial compression. (C) 2015 Elsevier Ltd. All rights reserved.