Finite Element Analysis of Concrete Columns Reinforced with FRP: Load-Strain Behavior

This study looks into the axial strength of round concrete columns that are reinforced with GFRP bars and spirals. Even though a clear consensus has developed on using FRP bars for flexural and shear strengthening of concrete structures, the role of FRP as longitudinal reinforcement in columns subjected to axial compressive stresses is not well understood. The research assesses how well these columns function when a force acts along their axis using an approach with the help of a software called Abaqus which is a finite element software. Twelve large-scale RC columns were initially tested under concentric axial loads are simulated to study their behavior under different configurations of reinforcements. The researchers in this study simulated the behavior of concrete material with the use of a Concrete Damage Plasticity (CDP) model which opted a failure criterion based on tensile and compressive damage. The experimental results were compared based on the maximum axial load capacity (Pmax) achieved before failure. The numerical and experimental results were found to give good agreement with a ratio of 0.92. The research discovered that the axial load capacity of GFRP-reinforced columns is the same as that of conventional steel-reinforced columns, with the longitudinal GFRP bars carrying 5% to 10% of the maximum load. Also, it was observed that closely spaced smaller GFRP spirals can confer a better ductility and confinement efficiency as compared to larger diameter spirals with widely spaced. According to Study, a Numerical Model for a GFRP-reinforced concrete column can effectively predict the axial strength of GFRP-reinforced concrete columns. According to the study, GFRP bars should be accounted for in design calculations as their exclusion causes an underestimation of the column’s ultimate capacity. Further refinement of the model's accuracy needs a focus on the role of diverse loading conditions, GFRP material properties, and column sizes in due course.