Inelastic Performance of High-Strength Concrete Bridge Columns under Earthquake Loads

Despite its importance in the seismic performance of an overall structure, our understanding of the ductility capacity of high-strength concrete (HSC) columns under various loading conditions is relatively limited compared to that of normal-strength concrete (NSC) columns. This study aims to evaluate the seismic performance of HSC columns through a numerical analysis approach. Based on the smeared crack concept, the analysis model consisted of material models for concrete and embedded reinforcement. The brittle behavior and smooth crack surfaces of HSC are some of its main drawbacks in engineering practice. In the proposed models, the shear retention mechanism along the crack surface correctly considered the smooth crack surfaces of HSC, and the confining effect of the column core was taken into account by modifying the concrete compressive model according to an appropriate confinement model for HSC. As part of the investigation, five large-scale HSC columns were constructed and tested under simulated seismic loading. The proposed numerical method was applied in predicting the seismic performance of various HSC columns tested in this research program and obtained from other research in the literature. The analytically predicted hysteretic behavior, ductility level, and failure mode of the columns showed reasonable agreement with experimental data.