Lateral behavior of rectangular concrete columns reinforced by partially debonded high-strength reinforcements based on a proposed equivalent stress block

This paper used partially debonded high-strength reinforcements (PDHSR) to develop self-centering reinforced concrete (RC) columns. The experimental results showed that the RC columns with PDHSRs had slighter seismic damage, more stable seismic resistance and smaller residual drift up to a large lateral drift compared with the RC columns with normal steel rebars. To simulate the lateral behavior of RC columns with PDHSRs for satisfying the requirements of performance-based design, this paper emphasized the prediction of the lateral behaviors of the RC columns with PDHSRs subjected to seismic load. Firstly, the basic information of the experiments was briefly introduced, secondly, the calculation method considering the steel-bond slip to predict the lateral behaviors of the RC columns was described in detail. Furthermore, several equations for calculating the neutral axis depth of the rectangular column section were proposed without enormous mathematical iterations. Several RC columns with normal steel rebars and the tested columns with PDHSRs were used to validate the applicability of the proposed calculation method. The results proved that the lateral behaviors of them can be predicted with good agreement. Finally, a parametric study was conducted based on the proposed calculation method to discuss the influences of some key structural parameters on the lateral behaviors of the RC columns with PDHSRs. Through regressive analysis, a simplified formula was developed for evaluating the effective lateral yield stiffness of RC columns with PDHSRs.