This document has been written to assist tunnel designers, contractors and owners in understanding the benefits of and limitations in the use of fibre reinforcement for precast concrete segments for tunnel linings, installed using tunnel boring machines. Guidance is also provided on specifications and testing. Fibres can be used as reinforcement in precast concrete segmental tunnel linings, either, most commonly, as “fibre only” (as ‘Primary’ reinforcement) or in combination with conventional (bar) reinforcement - a “combined solution” (as ‘Secondary’ reinforcement). The state of the art is defined by a large number of reference projects, where fibre reinforced concrete (FRC) segments have been used successfully. Projects using FRC segments report the following benefits of its use:
• Excellent durability;
• Damage due to handling and installation is minimized;
• Performance in the relevant Ultimate and Service Limit States (ULS and SLS) can be reliably
demonstrated;
• Reduced damage of segments;
• Overall manufacturing costs are lower than for conventionally reinforced concrete;
• A lower carbon footprint.
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