Internal Joint Bonding of Prestressed Concrete Cylinder Pipe: The Improbable Project

Located in North Texas, this project required navigation through over 20 mi of sloping 72-in. raw water prestressed concrete cylinder pipe to install internal bonding wires at each joint. The work required demolition and removal of the 2.5-in. of interior concrete to expose the steel cylinder and spigot ring of the pipe, installation of three bond wires across each joint via thermite welding, application of coating to the wires and welds with 100% volume solids epoxy, testing electrical resistance, and grouting the concrete cutout. The 72-in. diameter pipeline provides raw water for treatment and distribution to 1.7 million people, as well as water required at a local power generation plant, so project timelines were extremely tight. The total project consisted of approximately 4,325 joints, requiring approximately 13,000 bond wires, 26,000 thermite welds, cases of epoxy and pallets of cement and sand, and it was all completed in 44 working days.