Fiber glass reinforcement in tunnelling applications

The presented study deals with the possibility of replacing the traditional steel reinforcement with fiber glass bars, with particular reference to Tunnel precast segments. The solution is mainly suitable, and then proposed for the provisional parts of the underground tunnels and underground hydraulic tunnels. In the first case, the advantages are related to the easiness in the demolition and disposal phases. In the last case the technique can be very useful in avoiding the problem of corrosion of the traditional steel rebars, due to an aggressive environment. A further interesting application for the fiberglass bars is related to the definition of a skin reinforcement in tunnel segments with steel traditional bars. Experimental tests on full-scale precast segments with fiber glass reinforcement are described and discussed in the paper, and the obtained results are compared with the response of traditionally reinforced elements. In particular bending tests and point load tests are carried out with a system suitably designed and realized. On the basis of the experimental outcomes, it can be remarked that it proposed solution gives very promising results.