Application of Fiber - Reinforced Concrete in Tunnel Construction: Innovations and Challenges

Summary

Abstract

The introduction of fibers into the testing of concrete mixtures, particularly in the post-elastic zone, induces positive changes ranging from mild to significant, depending on a variety of factors including the strength of the concrete matrix, type of fibers, elasticity modulus of the fibers, fiber strength, surface bonding characteristics of the fiber to the concrete matrix, fiber content, fiber orientation within the matrix, and the effects of aggregate size. The use of concrete combined with steel fibers contributes to the plastic behavior of this type of material, which is especially suitable for applications where traditional reinforcement is difficult to implement, such as in tunnel linings. Modern demands in the field of civil engineering continuously require the introduction of new technologies to achieve higher quality, more durable, and more economical materials. In this context, this paper presents the application of fiber-reinforced concrete for the construction of the primary substructure of tunnel structures. Before being used to create the primary support of the tunnel structure, experimental-theoretical analysis and modeling of the applied fiber-reinforced concrete was conducted. The main scientific contribution of this paper is the use of the obtained laboratory characteristics of cylindrical samples (the working σ-ε diagram of fiber-reinforced concrete) for the calculation of tunnel linings. A review of the research community shows that until now, it has not been possible to apply the working σ-ε diagram of fiber-reinforced concrete in a digital format, thus, from this perspective, the presented paper represents an innovation.