Development and testing of new precast concrete tunnel segments reinforced with GFRP bars and ties

Abstract

Tunnels play a key role in assisting the movement of people, goods, and special services. The functionality of tunnels depends on the structural and durability performance of their lining systems. Replacement of steel reinforcement with non-corroding glass fiber-reinforced polymer (GFRP) bars is a viable solution to avoid the corrosion problem in precast concrete tunnel lining (PCTL) segments. This paper presents the results of an experimental study conducted to investigate the structural performance of GFRP-reinforced PCTL segments. Three full-scale tunnel segment specimens were fabricated and tested under bending load. The specimens measured 3100 mm in length, 1500 mm in width, and 250 mm in thickness. The investigated parameters were the type of reinforcement (steel and GFRP) and concrete compressive strength (40 MPa and 80 MPa). Test results indicated that the tested specimens failed with a desirable flexural failure mode. Replacement of steel reinforcement with GFRP bars enhanced the load carrying capacity and deflection at peak load by 33% and 50%, respectively. In addition, increasing the concrete strength enhanced the cracking load, post-cracking stiffness, and ultimate load by 28, 7, and 17%, respectively.