The deterioration of reinforced concrete infrastructures is primarily caused by corrosion of steel reinforcement, particularly in aggressive environments, which significantly reduces expected service life and intensifies maintenance needs. For such a reason, in the civil engineering field, Glass-fiber-reinforced polymers (GFRP) are emerging as an alternative to steel thanks to their high mechanical performance and intrinsic resistance to corrosion. Nevertheless, their actual sustainability must be verified through an assessment that considers long-term durability, life-cycle environmental impacts, and economic feasibility. Through an integrated methodology, this thesis evaluates the replacement of steel reinforcement with GFRP in bridge deck applications. First, a comprehensive literature review examines degradation mechanisms observed experimentally, such as moisture diffusion, fiber leaching, matrix plasticization, and interface debonding.