When FRP manufacturer Composite Advantage was asked to supply composite pile jackets for a waterfront application, it turned to nearby neighbour FiberSystems.
“We specialise in very large FRP composite parts up to 100 ft. for bridge and waterfront infrastructures,” says Composite Advantage President, Scott Reeve. “This was an application where the best approach was to source a pipe expert like FiberSystems.”
Composite Advantage explains that a New Zealand waterfront structure’s circular piers were eroding due to salt water, air and sun exposure. Concrete stay-in-place forms were used to repair the piers but corrosive conditions dictated the need for pile jackets for each of the piers. “FiberSystems had the mandrel sizes and the right manufacturing process to tackle the job,” says Reeve. “If a customer request falls outside our core competency, we’re able to use our network to meet that need.”
According to Composite Advantage, twenty-four ounce fabric knitted from carbon and glass fibres, 50 in. wide by 17 ft. long, was hand laid up in two sections around mandrels 18”, 20”, and 24”in diameter. Once the sleeves were custom fabricated, they were removed and split lengthwise. The outer edge of one side of the cut and the inner edge of the opposing cut were pre-sanded to facilitate easy bonding. Once installed, a special mortar is used to fill the space between the FRP jacket and the concrete pillar, creating a corrosion resistant armor against the elements.
“It was a labour intensive process,” says Tim Morton, Vice President of Operations for FiberSystems. “We had to adapt the process to meet the criteria needed to make the pile jackets. But we’re known as a fabricator’s fabricator. We are able to take a customer’s requirements and determine the best approach whether it means customising processes or in some cases, creating new methods to complete a job.”
FiberSystems says it used unpigmented vinylester resin to produce a total of 17 18”, inside diameter, five 20” inside diameter, and seven 24” inside diameter pile jackets. The FRP sleeves were shipped to New Zealand in October.