This study presents a comparative experimental investigation on the structural behaviour of concrete-infilled and partially encased cold-formed steel composite columns (CFSCC) incorporating Basalt Fibre Reinforced Self-Compacting Concrete (BFRSCC). Two built-up column configurations are fabricated using sigma sections: a face-to-face (closed) arrangement fully infilled with BFRSCC, and a back-to-back (open) arrangement partially encased with BFRSCC. Axial compression tests are performed to evaluate and compare the load-bearing capacity, axial shortening, ductility, and failure mechanisms of the two systems. The results show that the incorporation of basalt fibres enhances axial performance in both configurations due to improved confinement, crack bridging, and bond behaviour at the steel-concrete interface. The closed BFRSCC-infilled column (CI-BFRSCC) exhibits superior performance, carrying approximately 1.25 times the load of the partially encased counterpart (PE-BFRSCC) and demonstrating greater ductility, attributed to the uniformly confined concrete core and delayed local buckling. The experimental results are validated through ABAQUS finite element simulations, which show good agreement in ultimate strength and failure modes, confirming that the developed numerical model is reasonable and feasible. Since no dedicated design provisions exist for CFSCC with BFRSCC, the experimental results are compared with predictions from IS 11,384 (2022) as well as international design standards, including Eurocode 4, AISC 360 − 16, and AS/NZS 2327. The modified theoretical approach yields slightly conservative yet reliable predictions, with (Pu, Exp / Pu, The) values ranging from 0.85 to 1.27 across all codes, confirming its suitability for axial strength prediction. A Life-Cycle Assessment (LCA) is further conducted to quantify the embodied carbon emissions of all column types across production to end-of-life stages. The findings indicate that BFRSCC columns achieve a favourable balance between mechanical performance and environmental impact. Overall, the study demonstrates the suitability of BFRSCC for enhancing the strength, ductility, and sustainability of CFS composite columns, supporting their application in structures requiring high energy absorption and improved life-cycle efficiency.
Sharon et al. (Sun,) studied this question.