In co-operation with the engineering firm IWA of Minden, the option of constructing a new pipe in an open trench was quickly dismissed as it would be too costly and complex. A new construction would have meant the need for costly groundwater management.
“It was for this reason, and because there were no major hydraulic load problems, we decided for a repair from the inside.
“With this option we used a close-fit-liner, which meets the on-site structural requirements and can be installed under the given circumstances. At the same time we trusted the Janssen Lateral Rehabilitation Process. No other lateral repair system can connect and seal these laterals so well,” Mr Schmit said.
This solution is based on a special packer and two component resin. After a series of protruding laterals, and other obstructions were removed using a cutting robot, the actual rehabilitation could begin.
The packer was placed at the damaged spots and inflated by compressed air. Then the liquid two component resin was injected through the damaged areas.
Managing Director of the Goch-based service company Janssen Umwelttechnik said “The resin fills the voids, displaces the groundwater and bonds with the bedding material – this way the actual sealing and stabilising happens on the outside of the pipe.