What is the best type of marine encapsulation?
Piles protected in the tidal zone by epoxy-filled FRP jackets.
The process of pile encapsulation has existed for over a century. However, the technological advances in materials and equipment have made this process a far more effective and economical method of protecting an expensive capital investment.
The Best Type of Encapsulation: Epoxy-Filled Fiber-Reinforced Polymer (FRP) Jackets
The best type of encapsulation currently available involves the installation of a fiber-reinforced polymer (FRP) form or jacket around a structural member. This jacket is sealed at the bottom edge to the structural member.
Rows of “stand-offs,” which have been previously attached to the inner face of the jacket, assure a uniform annular space between the structural member and the jacket itself. This annular space is commonly 1/2 inch, but can be varied depending upon individual specifications.
The annular cavity is then filled with a two-part epoxy comprised of a resin and a hardener to which a fine aggregate such as silica sand is added. This epoxy fills any existing voids and effectively bonds to both the structural member and the FRP jacket, creating a monolithic structure.
The protection that this type of encapsulation provides - both from the effects of corrosion and from physical damage - is extraordinary. This technique is often employed on structural members in the tidal zone - that extremely corrosive environment where cathodic protection systems cannot provide continuous protection.