A Theoretical Analysis Incorporating Empirical Formulas for Minimum GFRP Circular Spiral Reinforcement in Concrete Column Confinement

This study investigates the influence of Glass Fiber Reinforced Polymer (GFRP) spirals on concrete column confinement. GFRP reinforcement is a useful alternative to traditional steel reinforcement because it offers certain advantages, like corrosion resistance and improved durability. GFRP spirals are lighter than the steel ones, providing higher tensile and fatigue strength. On the other hand, steel spirals are more affordable and offer higher compressive strength. While the traditional steel model aligns with the ACI code specifications, GFRP bars call for a different approach in determining the minimum spiral reinforcement. This study highlights the way that longitudinal reinforcement bars, which are conventionally neglected, influence the minimum spiral reinforcement requirements. The reinforced concrete models that may be applied in the future, should take into consideration both the confinement effectiveness of GFRP bars and the influence of longitudinal reinforcements to ensure structural integrity.