Generic 3D conceptual stress-strain model for concrete confined with fiber reinforcement polymers

This study proposes a generic 3D conceptual stress-strain model for concrete confined with fiber reinforced polymers (FRPs), integrating both synthetic and natural fiber materials. The proposed model addresses limitations of existing confinement models by providing a unified framework that accurately predicts the stress-strain behavior of FRP-confined concrete across various fiber types and applications. The model was developed by thoroughly analyzing experimental data and conducting a comprehensive review of existing stress-strain models. Key challenges, such as variations in ductility and strength between synthetic and natural fibers, were systematically addressed to enhance the model’s predictive accuracy. The model's capability was validated through comparisons with experimental data, demonstrating its reliability in capturing the complex interactions between FRP materials and concrete. The proposed model can enhance the analysis, design, and sustainability of FRP-confined concrete structures, advancing confinement methodologies and in particular promoting the use of natural fibers as sustainable materials in construction. • The model features a 3D surface representation, capturing axial-lateral stress-strain interactions for improved predictive accuracy. • Experimental validation confirms its effectiveness in modeling stress-strain behavior across various fiber types. • The model provides a unified framework applicable to analysis, design, and optimization of FRP-confined concrete structures.