Comparison of the condition of steel fiber-reinforced shotcrete with water-glass and alkali-free activators after more than 20 years of service in a subsea road tunnel

• Main Authors: Manquehual, Cristobal Javier, Jakobsen, Pål Drevland, Holter, Karl Gunnar, De Weerdt, Klaartje, Danner, Tobias Alexander, Bruland, Amund
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Nordkapp
• Online Access: https://hdl.handle.net/11250/3041648

The in-service condition of steel fiber-reinforced shotcrete installed more than 20 years ago as single-shell rock support lining in the Nordkapp subsea road tunnel was investigated. The novelty of this study is the comparison of shotcrete with water–glass and alkali-free activators in a saline groundwater environment. The lowest shotcrete density was obtained at joints between two adjacent shotcrete layers. In the case of alkali-free accelerator, ettringite enrichment was observed in these joints. Leaching appeared to be the main degradation mechanism in the outermost 10–15 cm towards the traffic room.