Fibre-reinforced sprayed concrete for use in permanent tunnel lining application

The use of fibre reinforced sprayed concrete for permanent tunnel lining has recently undergone rapid development as it represents an appealing structural alternative to cast-in-situ lining due to lower capital/operational costs and carbon footprints. However, current standards and recommendations may not sufficiently persuade the tunnel construction industry to adopt this material. For the permanent loading conditions involving primary and secondary linings, mechanical characterization of Fibre Reinforced Concrete (FRC) panels is necessary: it is hence recommended to get residual post-cracking strengths in accordance with method “B” of recently updated EN 14488-3. To the contrary, energy absorption panel tests provide sufficient information in case of temporary stages. This study regards the evaluation of post-cracking properties of concretes reinforced with macro-synthetic fibres (MSFRC) for use in permanent tunnel linings through standard panel tests in accordance with EN 14487-1.