Recently, the city has undertaken two large diameter sewer rehabilitation projects: one planned, the Missouri Avenue outfall, while the other, Charles Street outfall, was unplanned and required emergency repairs. Both of these projects utilized a fairly new and innovative process to increase the structural integrity of the structures while increasing the flow by reducing the friction coefficient of the pipe itself. This process is called quadex lining with fiber reinforced geopolymer.
The quadex lining system is a robotic application where the geopolymer is broadcast by an axial motion applicator that articulates in a conical pattern inside of the existing pipe. This robot is then navigated back through the pipe leaving a new fully structural, corrosion resistant monolith lining. The method of application allows the lining of round, oval and arched pipe that may also have bend and other penetrations or obstruction in the composition of the original pipe materials.
The GeoKrete Geopolymer is a formulated mortar comprised of aluminosilicate powder with an alkaline activator to form a monolithic mineral polymer with ceramic properties. Geopolymer cures through a process of polycondensation and possesses proven, high early and long-term compressive strength. The chemical composition of GeoKrete Geopolymer makes it inherently resistant to the microbial induced corrosion prevalent in many sewer environments.
So, what does that all mean in terms we can understand? Basically, this system spins casts a liquid material inside of an aging pipe. This material is as strong, if not stronger, than the pipe itself once it has cured or set up giving it a ceramic-like coating. Because of this coating, it is much smoother even with the reduction in pipe diameter, we are able to move more water more efficiently due to surface friction being lower. Furthermore, all of this is done quickly without the heavy costs of pipe removal and reconstruction.