Strength Behavior and Ultimate Capacity Prediction of Self-Compacting Concrete-Filled Thin-Walled Medium-Length Steel Tubular Columns under Eccentric Compression

The development of self-compacting concrete-filled thin-walled steel tubular columns is a potential strategy to ease the challenge of conserving resources in society, which are largely consumed by the quickly developing civil industry. However, the application of these columns in the civil industry is rare due to insufficient research, especially research concerning the strength behaviors of the columns under eccentric compression. Therefore, the eccentric compressive behaviors of medium-length tubular columns made up of self-compacting concrete and thin-walled steel with circular sections were experimentally studied in the present paper. The feasibility of predicting the columns' ultimate capacities using existing design codes was explored, and then comparisons between the predictions and experimental values were carried out. The results showed that the eccentric compression columns had a failure morphology, buckling together with a lateral deflection while they were moved from the bottom to middle positions as the wall thickness increased. Moreover, the ratios of the predicted ultimate capacity of the eccentric compressive columns to the experimental values were within the range of 0.35 to 0.94. This indicates that the predicted ultimate capacity is conservative and safe. The codes AISC-LRFD and JCJ 01-89 achieved the most conservative and the most precise predictive results, respectively. Additionally, the decrease ratio of the predicted ultimate capacity of the eccentric compressive columns to the experimental values was more evident than that of axial compressive columns. This paper can serve as guidance for the design and application of these columns, as well as foster a sustainable and resilient civil industry.