GFRP Bars and CSA-based Concrete for Sustainable Tunnel Lining Segments: not a challange, but an opportunity

The need for transition towards alternative and sustainable solutions in the tunneling sector is underscored by global data. Italy ranks second worldwide in both the number and length of tunnels, following China, with many surpassing 30 years of operation. Enhancing sustainability and durability requires interventions in both materials, such as concrete and its reinforcement, and the precast concrete segmental lining production process. Partially substituting clinker with sustainable binders like calcium sulfoaluminate (CSA) cement and replacing steel with non-metallic materials such as glass fiber reinforced polymer (GFRP) can mitigate environmental impact. This paper presents a case study investigating the use of GFRP-reinforced CSA-based concrete to enhance sustainability and durability in tunnel linings.