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
Cristobal Javier Manquehual, Pål Drevland Jakobsen, Karl Gunnar Holter, Klaartje De Weerdt, Tobias Danner, Amund Bruland
Abstract
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.
Topics & Concepts
ShotcreteSubseaMaterials scienceGeotechnical engineeringLeaching (pedology)UnderwaterComposite materialGeologySoil waterSoil scienceOceanographyConcrete and Cement Materials ResearchInnovative concrete reinforcement materialsConcrete Corrosion and Durability