Strength behavior of circular concrete-filled steel tube stub columns under axial compression: A review

This paper reviews the compressive strength of circular concrete-filled steel tube stub columns (CFST-SCs). The material compositions for compressive behavior experiments of circular CFST-SCs are summarized, and the confinement effect and failure mode are discussed. Experimental results of 367 circular CFST-SCs are utilized to evaluate applicability and reliability of six international design specifications for predicting compressive strength. The reliability of prediction results under different influencing factors is discussed. The outcomes revealed that all specifications yielded conservative predictions on the strength capacity of the circular CFST-SCs. AS/NZS 2327 and CAN/CSA S16-01 bring the most conservative predictions. On average, EC 4 better captures the strength capacity of small-size circular CFST-SCs provides an adequate reliability level for structural design. The study provides summations of measures preventing buckling failure of circular CFST-SCs and the applicability of existing guidelines for assessing their axial strength.