Vipel technology was used for a custom composite liner.
CIPP eliminated the need for pipe excavation and replacement.Expansion plans by the San Diego Airport Authority put a new terminal over a 96 inch (2438 mm) diameter concrete sewer pipeline. The pipe was 25 ft (7.6 m) underground and not designed for the structural loads the new project would add. Because pipe excavation and replacement would have created headaches for taxpayers and air travelers alike, engineers explored trenchless technologies.
Keeping the wall thickness of the new liner under 1.26 inches (32 mm) was critical to ensure that the upgraded pipe could handle current and projected volumes. To make the liner strong enough, slip-lining would have added approximately 12 inches (305 mm) of wall thickness, and conventional CIPP would have added 2.07 inches (51 mm).
For a solution, general contractor Charles King Co brought in Insituform Technologies, a provider of technologies for rehabilitating sewer, water and other underground piping systems without digging, to install a custom, 1700 ft (518 m) long iPlus Composite liner.
iPlus Composite is a carbon and/or glass fibre reinforced CIPP solution. Reinforcing fibres are integrated into the pipe wall to create a uniform laminate structure with improved physical properties.
Use of the Insituform iPlus Composite at the airport resulted in a pipe strong enough to withstand the new structural loads at a wall thickness 40% less than conventional CIPP.
Insituform used AOC's Vipel resin for the project.
"The Vipel 102NA resin is specially designed to efficiently wet out the reinforced liner,” reports Bill Moore, AOC Product Leader for CIPP. “The resin technology optimises the performance and superior mechanical properties of the carbon fibre-reinforced composite structure.”
With no appropriate manhole available for the installation, site workers created a single access point for two inversions in opposite directions.
The job established a new benchmark for iPlus Composite technology, which to date had not been used for a water inversion greater than 200 ft nor in a host pipe larger than 60 inches in diameter.