Abstract The possibility of adopting glass-fiber reinforced polymer (GFRP) composite bars in tunnel segments as a substitute of the traditional steel reinforcement has been demonstrated. Nevertheless, this application requires a curvilinear shape for the reinforcement, and thus a different production process and rebar geometry. The aim of the paper is the experimental evaluation of the physical and mechanical properties of non-conventional GFRP rebars. The test procedures and obtained results are highlighted and compared with the acceptance criteria available for straight pultruded rebars. Finally, the presented outcomes show the suitability of GFRP non-conventional bars as reinforcement for precast concrete segments in tunnel applications.