The Montreal Metro operated by the "Société de transport de Montréal" (STM) was inaugurated in 1966. It is an entirely underground system that spans over 72 km and consists of four lines serving 68 stations. Since 2004, the STM has been investing in refurbishing the infrastructure of the underground metro. One of the major elements in the STM’s refurbishment program is the replacement of the 53-year old ventilation system.
Construction of the majority of the new ventilation stations consists of the following phases:
- Excavation of a shaft from ground level to the metro level
- Excavation in the rock bed by micro-blasting and road headers
- Application of steel lattice girders and shotcrete for initial ground support
- Installation of a membrane to ensure water tightness
- Installation of mechanical and electrical equipment, and construction of the station’s external structure on the ground level
Since 2017, Sika-King has supplied the shotcrete on all five ventilation station projects. The shotcrete supplied on these projects is a dry-mix in prepackaged bulk tote bags, applied using Sika Aliva? AL-252 spraying machines. The product used for the 135 mm structural layer is King MS-D3 X STC, containing pre-mixed steel fiber and accelerator. This mixture was specially formulated for this project to meet the specified mechanical requirements.
The product used for the surface smoothing layer was King MS-D1, a standard shotcrete mixture without accelerator or fiber. The contractors opted for prepackaged dry-mix instead of ready-mix shotcrete in order to eliminate lost waiting time for trucks to arrive and allowed them to work on their own schedule.
King MS-D3 X STC
Beton Projeté M.A.H.