Waterproofing and H2S protection of an existing concrete sewer tunnel, at G.E. Booth (Lakeview) Wastewater Treatment Plant, Mississauga, Ontario, Canada.
Tunnel has an internal diameter of 1.52 m (5’) and total length is over 500 m (1,650’).
After stopping all active water leaks, the surface of the tunnel was sandblasted to remove soft concrete layer, and to obtain clean surface.
Some deeper delaminated sections were repaired using Gem-Plast TC, a polymer-modified cementitious mortar.
2-coat system was used consisting of Cem-Kote Barrier Cote 100 that was spray applied and brushed to further level the substrate, followed by a coat of Cem-Kote Flex CR that was applied “wet to wet”. Two coat application and brushing assure a continuous membrane and eliminates formation of pinholes.
The project was carried out in 2017 and inspected in 2019. No deterioration or debonding, even the at the bottom were found. It is currently used as odour control tunnel.
Figure 1 Concrete Surface Deterioration
Figure 2 Years no Debonding or Deterioration
Figure 3 Inspection after 2 Years no Debonding or Deterioration