Two-scale basalt fibers reinforced concrete shield tunneling segments for underground constructions

Abstract

In this paper, two-scale Basalt fibers reinforced polymer (BFRP) rebars reinforced arch (BRRA) technique was developed through applying BFRP rebars to macroscopically reinforce concrete shield tunneling segments (STSs). BFRP minibars were mixed into concrete as the micro reinforcements. Six two-scale BRRAs were prepared with content of minibars changing from 0%, 0.5% to 1.5%. Full-scale flexural experiments were performed to reveal the mechanical performances of the BRRAs. With higher minibar content, the utilization ratio of the BFRP rebars is much greater and the BRRA has longer elastoplastic deformation, higher bearing capacity and better ductility. Long elastic deformation of BFRP rebars and reinforcing mechanism of BFRP minibars improve the bearing capacity and ductility of the BRRA.