- 1). Ensure the appropriate city and county officials have been contacted and approval received prior to accessing the PCCP in need of repair. As PCCP applications are so often associated with city and county lines, the local authorities may want to complete the repairs themselves to avoid possible safety issues.
- 2). Gain access to the PCCP needing repair. As noted, PCCP is often used in underground applications. Begin by determining the exact location and depth of the line (city and/or county records will indicate this -- if a private PCCP line needs repair, you will have noted its location) and digging approximately 2 feet to either side so as not to strike the damaged pipe.
- 3). Remove the damaged area of PCCP if possible. The pipe size may not permit this; if not, work on the pipe in its current location. Thoroughly clean the cavity and dry completely, including high-pressure power washing if necessary to remove sediment. This preparation is necessary prior to the application of the repair material. Repair is needed most often as a result of damaged or corroded prestressed wire mesh used in PCCP. Avoid treading on the recently cleaned interior of the pipe to maintain its cleanliness.
- 4). Apply carbon-fiber reinforced polymer sheets (FRP) horizontally and length-wise to the internal circumference of the pipe. FRP has become the repair material and process of choice for both big and small PCCP repair applications, according to Composites World, an industry trade association. Formerly, repairs were made using sectioned steel liner, welding them together and applying grout between the sections. Not only is this process more labor intensive, it requires removal of the pipe, regardless of size, making it prohibitive for many repairs.
- 5). Cut the FRP pieces to the desired length. Apply an epoxy primer followed by an epoxy putty applied with a trowel. This also helps smooth out the epoxy applications. Soak the FRP pieces in an epoxy saturant and apply to the inside circumference of the PCCP. Using a metal roller will help to remove air bubbles and better seal the FRP. Coat the carbon fiber in one more layer of epoxy saturant.
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