Seismic performance of reinforced concrete column section with crimped steel fibre: a parametric study

The incorporation of fibres into the concrete matrix enhances its compressive stress–strain characteristics, improving the capacity of structural elements and overall seismic performance. While past studies have examined fibre effects at the material and curvature levels, the combined influence of fibre content, aspect ratio and concrete grade remains underexplored, and Indian seismic codes lack clear guidelines for fibre-reinforced concrete (FRC). This study presents the first development of fully non-linear Pu–Mu interaction curves for reinforced concrete columns reinforced with crimped steel fibres (CSFs), generated through validated sectional analysis in the SAP2000 software program. Using fibre-dependent non-linear material models, the study systematically evaluates varying fibre contents (0.25–1.50%), aspect ratios (55 and 82) and concrete grades (M20–M40), quantifying improvements in axial–flexural capacity. Results indicate that CSF significantly enhances curvature ductility (up to 99.78%), ultimate moment capacity (up to 36.50%), plastic rotation (up to 163.45%) and overall Pu–Mu interaction behaviour, highlighting its potential as a key structural material. These findings provide a foundation for incorporating FRC into Indian seismic design codes, enabling performance-driven, seismic-resistant design strategies.