Article

Adishri D. Dhondrikar, VNIT; Dr. S. B. Borghate ,VNIT

Concrete-filled steel tubes (CFSTs) are used in constructions such as piles, caissons, columns, piers. Relative to conventional structural steel and reinforced concrete and provides huge tensile and compression capacities; the concrete fill prevents buckling of the steel tube and increases the capacity, stiffness and ductility of the section. Sometimes, reinforcement is used to strengthen and facilitate connection to adjoining members. Even though these properties are well favouring, the use of CFST in practice is rare because every design code gives different codal provisions. A study was carried out to enhance design norms for CFSTs without reinforcement bars under general loading. A model was made to reproduce test results subjected to both axial and combine loading and after validation model was used to study the strength and performance of CFSTs under general loading. The comparisons indicate that present design gives good resemblance of CFST capacity subjected only to bending or axial loads with experimental results by previous researchers but current provisions provide conservative values for the CFSTs under general combine loading.