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@article{207202,
        author = {Mohit Sambhaji Patil and Prof. U.L.Deshpande and Prof.R.A.Chougale},
        title = {PERFORMANCE EVALUATION OF LIGHTWEIGHT CONCRETE-FILLED STEEL TUBE COLUMNS: STRUCTURAL BEHAVIOUR, MODELLING, DESIGN, AND RESEARCH NEEDS},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {3},
        pages = {97-113},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=207202},
        abstract = {Lean concrete filled steel tube (LWCFT) columns consist of a hollow steel section combined with a reduced density cementitious core which is intended to reduce the structural dead load of LWCFT columns. Structural performance of LWCFT columns retains the benefits of composite confinement, buckling restraint, construction advantages as well as cost saving similar to conventional CFST member. The performance of the confining tubes is regulated by the steel geometry and concrete strength. However, the lightweight aggregate type, density, elastic modulus, wet-dry state, interface bond and core-load compatibility also play significant roles. This review critically evaluates experimental, analytical, numerical, code-based and data-driven approaches used for LWCFT and closely related CFST columns. A structured literature review was conducted across the following databases: Scopus, Web of Science, ScienceDirect, SpringerLink, Wiley Online Library, Taylor & Francis, IEEE Xplore, and Google Scholar. This was for studies available until 16 July 2026. After removal of duplicates, screening, assessment of eligibility for full text and appraisal of quality, 28 scholarly studies, mainly peer-reviewed, were included for synthesis. This was supplemented by major standards and reference books. It is evident that circular tubes tend to induce a more uniform confinement as compared to square or rectangular tubes. Lightweight core can improve structural efficiency but may sacrifice initial stiffness and alter dilation, bond, creep, and post-peak response. The axial capacity is determined by the steel ratio, confinement index, density-strength relationship and slenderness of the member. Under applied eccentric, cyclic, fire, sustained loading the reduced modulus and high moisture sensitivity of light weight concrete need to be treated explicitly. Finite-element models based on concrete damaged plasticity can reproduce the global response of a core when dilation and contact and imperfections are calibrated. Fast machine learning models are capable of predicting capacity quickly, but they are weakly validated for lightweight-core data. The key deficiencies include the lack of full-scale testing, the inconsistent reporting of density plus aggregate characteristics, and the limited evidence concerning long-term performance plus fire resistance, together with no design provisions optimised for LWCFT columns. A coordinated data, experimental, and numerical approach is proposed to establish trustworthy resistance factors and ductility limits and performance-based design criteria.},
        keywords = {lightweight concrete; concrete-filled steel tube; composite column; axial compression; confinement; finite-element analysis; machine learning.},
        month = {August},
        }