Experimental Behaviour of Precast Tunnel Segments in Steel Fiber Reinforcement with GFRP Rebars

The interest in using fiber reinforced concrete (FRC) for the production of precast segments in tunnel lining, installed with Tunnel Boring Machines (TBMs), is continuously growing, as witnessed by the studies available in literature and by the actual applications. The possibility of adopting a hybrid solution of FRC tunnel segments with Glass Fiber Reinforced Polymer (GFRP) reinforcement is investigated herein. Full-scale tests were carried out on FRC segments with and without GFRP cage, with a typical geometry of metro tunnels. In particular, both flexural and point load full-scale tests were carried out, for the evaluation of the structural performances (both in terms of structural capacity and crack pattern evolution) under bending, and under the TBM thrust. Finally, the obtained results are compared, in order to judge the effectiveness of the proposed technical solution