Plain concrete, which is strong in compression but weak in tension, has historically been reinforced with steel bars to withstand tensile stresses, resulting in Reinforced Concrete (RC). In the last decades, studies and research investigated a wide range of reinforcement alternatives, including composite materials, like Glass Fiber-Reinforced Polymer (GFRP), mainly because of the growing problem of corrosion of steel bars in ordinary RC elements and related maintenance problems with consequent high costs. The introduction of GFRP reinforcing bars in RC structural elements provides several advantages such as high resistance to corrosion, high tensile strength, light weight, electromagnetic transparency and sustainability, making them particularly suitable for harsh environments and retrofitting applications.