Pultruded (FRP/Composite) Products
“Pultrusion” is manufacturing process used to manufacture composite profiles which are an alternative construction material without many of the performance disadvantages of conventional materials of construction such as aluminum, concrete, steel and wood. A pultruded structural member, commonly referred to as an “FRP” (Fiber Reinforced Polymer) will not corrode, decay, or spall, thereby reducing maintenance costs and future replacements. The FRP composite system resists creep significantly better than vinyl (PVC) materials because FRP profiles are made with high quality thermoset resin systems whereas PVC is a thermoplastic. An example is comparing plastic PVC conduit compared to fiberglass boats. FRP piles are easier to install in harder soils than vinyl sheet piling due to the inherent stiffness and compression strength.
Some of the typical marine applications are:
- Retaining Walls
- Erosion Control
- Flood/Storm Surge Protection
- Bridge Abutments
- Containment/Cut-Off Walls
- Stay-In-Place Forms
- Land Stabilization
- Wave Breaks
- Sheet Pile Caps & Connections
- Waler Systems
The production of a pultruded product is quite unique as it is the opposite of extrusion. FRP profiles are pulled out of a die.
High strength E-glass fiberglass in the form of roving, engineered fabrics and continuous filament mat is pulled into a “wet” out chamber. The fiberglass reinforcement is “infused” with an extremely durable, tough and environmentally stable resin, which “casts” the reinforcements in the correct orientation during the curing process in a continuous operation. Pigments and UV inhibitors are added to the resin to provide color stability and UV protection.
The Finished product is then pulled through the die and into the cut-to-length saw where it is cut and prepared for shipment to the job site.
The firm of Creative Pultrusions, Aluma Bank, PA. produces an FRP Waler Section appropriately named the “SuperWale®. It eliminates the need for timber, steel or concrete wale sections. The pultruded FRP wale section was specifically designed to replace wood, steel and concrete for applications where the environmental considerations require a high strength FRP wale section that will not rot, rust, spall or succumb to marine borers. SuperWale® can be installed above or below the waterline or in the transition area. The patented profile features a unique shape that allows the tie back rod to recess into the wale section. This feature increases human safety and decreases the possibility of damaging boats, personal watercraft or other high dollar assets in the event they rub against the FRP wale.
The installation of Composite/FRP/Putruded Sheet Piling is basically no different than the installation of any typical Sheet Piling profile. It can be via Water Jetting Equipment, Jack Hammer or your typical smaller, Excavator Mounted Vibratory Driver/Extractor or Free Hanging Vibro.
Pultruded sheet pile sections can be driven to elevation in clean sands and clay that exhibit a blow count N of 20 blows or less per foot as determined by the Standard Penetration Test (SPT). Numerous FRP sheets have been driven in soils with blow counts ranging from 20 to 30 with the aid of excavation and or a steel mandrel. The steel mandrel is fabricated to mimic the profile shape of the sheet. The steel mandrel is driven into the soils ahead of the FRP sheets to punch a profile through the stiff soil prior to driving the FRP sheet.
Depending on the drive ability and the hammer type, it is not uncommon for the sheet pile to display some signs of abrasion and mushrooming at the top due to the clamp pressure and vibration of the vibratory hammer. Most contractors will add some length of sheet and cut the sheets to grade after they have been installed.
Today, the demand for Pultruded/FRP Composite Sheet Pile Systems is in full motion. Manufactured with state of the art thermoset resins and high strength E-glass, via the pultrusion process, FRP products such as Creative Pultrusions patented SuperWale® System and SUPERLOC® sheetpiles are the product of choice for the test of time. Engineers, architects, home owner associations, and government agencies continue to specify SuperWale® and SUPERLOC® where low maintenance, aesthetics, and a superior design life are crucial to their projects.