Piles and Piling
The dry-wet cycle in marine environment leads to rapid corrosion of submerged piles. This is particularly significant around the splash zone.
The Problems with Common Jackets
Conventional FRP jackets are typically made of two half shells that are connected in the field around the piling and filled with concrete or grout. There are several major problems with these products:
- The jackets must be custom ordered in advance for the size of piling being repaired; wrong sizes could delay the project.
- The jackets are bulky adding cost for shipping and storage
- The seams along the sides of the jacket let moisture and oxygen in, resulting in continued corrosion of the pile
- From an engineering point of view, these seams are the weakest point in the jacket and they do not offer any confinement for the pile and the concrete or grout
When the US army Corps of Engineers undertook a massive study to select the best piling repair system, they cited the above shortcomings in their report and decided to only complete the investigation with PileMedic.
Timber, Concrete or Steel Piling
The procedure for repair and strengthening of piles (pilings) is virtually the same regardless of the materials of the original pile. The only exception is for load transfer in steel piles as explained below using ShearWrap and ShearClamp.
When strengthening is required, we create a new ring of reinforced concrete shell around the existing piling. These shells will be built using non-corroding Glass Fiber Reinforced Polymer (GFRP) Rebars that ensure long service life for the repaired pile. With this approach, the new concrete shell can be designed to have as much capacity as required, even to replace the 100% capacity of the pile if the original piling has 100% section loss!
The repair process begins by securing the required number of spacers around the pile at 2 to 3 feet on center. These spacers are typically 1 to 2.5 inches long to create a 1 to 2.5 inch thick annular space around the piling. If any reinforcing bars are required for strengthening of the pile, they will be snapped into the spacers. Four-feet wide PileMedic laminates are epoxy coated and wrapped around the pile to create a shell that is two-layers thick. Ratchet straps or zip-ties can be used to prevent th e unraveling of the jacket while the epoxy cures. Another 4-ft laminate an be similarly wrapped and overlapped with the previous ones by 4 inches. This process will be repeated as many times as required to create a jacket of desired height around the piling.
The bottom of the annular space must be sealed. This can be done by embedding the shell a few inches into the seabed. If the jacket does not extend to the seabed, ShearFlange or skirt pins can be used to create a seal at any elevation. Next, the annular space will be filled with grout or concrete using the tremie method or by pumping through the ports that we supply and can be inserted along th height of the jacket.