AXIAL BEHAVIOR OF HIGH-STRENGTH CONCRETE-FILLEDHIGH-STRENGTH SQUARE STEEL TUBULAR STUB COLUMNS

To investigate the fundamental behavior of concrete-filled steel tubes (CFSTs) consisting of high-strength materials, this study experimentally explored the axial performance of eight high -strength concrete-filled high-strength square steel tube (HCFHSST) stub columns considering various yield strengths of steel (fy from 566.90 MPa to 889.87 MPa).Thereafter, the compatibility between the strengths of steel and concrete was discussed.Simulations were also performed to evaluate the structural responses of the column, incorporating the crushing failure and load -carrying performance of concrete, the local and post-local buckling behaviors of the column, and the steel tubular confinement effect.Based on existing literatures, a test database including data on 170 CFST stub columns with high -strength materials was established.The calculations from various design codes were compared with the peak-loads of these 170 samples, which identified that Eurocode 4 afforded the closest predictions on average, while it was unsafe for columns incorporating conventional-strength steel and high-strength concrete.As for columns with compact sections, AISC 360 can be safely utilized for predicting the peak-loads.