Abstract: Fiber reinforced plastic FRP formed about concrete piles and columns. The FRP components generally includes an exterior shell and an interior protruding portions. The concrete filled FRP tubes are enhanced by prestressing the concrete core, thereby increasing the bond with the tube and placing the tube in an active hoop tension. The prestressing can be developed by either post-tensioning a series of strands(or tendons) that are placed inside the core, or by using expansive core materials which do expand upon curing and will therefore impose an active pressure on the confining tube. The bond can be developed by either internal resin grids, FRP spirals, FRP orthotropic grids, sand-resin coating, bonding agent or protruded ribs. The system can be used as a fender pile, bearing pile, bridge pier column, or any structural column. The system can be made by pultrusion, SCRIMP, REM, centrifugal methods or hand lay-up.

Abstract: Fiber reinforced plastic FRP formed about concrete piles and columns. The FRP components generally includes an exterior shell and an interior pultruted component. The exterior shell can include multilayers of fibers wrapped in straight hoop patterns in single sheets with or without longitudinal axial fibers. Alternatively the exterior shell can include angled wrapped fibers. The interior FRP pultruted component comes in various forms such as pultruted ribs, crossed attached ribs, interior co-axial concentric cylinders and additional shapes such as ones having an H cross-shaped pattern. The FRP materials can consist of fiber and resin such as a preferred embodiment of approximately 60% glass and 40% polyester. Other fiber type materials include but are not limited to glass, carbon, Kevlar, combinations thereof, and the like. Types of resin include but are not limited to polyester, vinylester, epoxy, combinations thereof, and the like.