STRUCTURAL offers industry leading experience in the repair and strengthening of prestressed concrete cylinder pipe (PCCP) using advanced technologies such as fiber reinforced polymer (FRP) composite strengthening sysetms and post-tensioning.
Pipe Strengthening with Composites
These structural strengthening systems are made of high strength fibers embedded in a resin matrix. The resin protects the fibers, maintains their alignment, and distributes the loads evenly among them. Fiber reinforced polymer (FRP) composites are thin laminates that are externally bonded to structural members using epoxy adhesive. The FRP significantly increases the capacity of concrete pipes. As with any other externally bonded system, the bond between the FRP system and the existing concrete is critical to achieve a composite behavior with the existing member. Accordingly, proper surface preparation is a key process for ensuring a successful FRP strengthening application. When bonding FRP systems to the inside of pipelines, considerations such as transient pressures and water absorption require a well designed, precisely installed end detail.
Pipe Strengthening with External Post-Tensioning
External post-tensioning refers to the method of post-tensioning in which the strengthening system is installed outside the structural element. External post-tensioning requires access to the sides and sometimes the ends of the member. Encapsulated unbonded monostrand post-tensioning systems are used to protect the tendons in corrosive conditions. Strands are protected at the anchorages using greased plastic sleeves and grease-filled end caps. Additionally, anchorage components are fully encapsulated in a high density polyethylene plastic covering.