On the waterfront: Composite sheet piles build on success

Although glass-fiber reinforced polymers (GFRP) have been used to build boats for decades, similar materials have been slow to catch on in the manufacture of other marine structures. That’s hard to fathom: Composite load-bearing piles are an ideal fit for waterfront piers, docks, seawalls and fendering systems. Unlike traditional piling materials — wood and steel — composites resist rot, insect infestation and corrosion — the three biggest problems that plague conventional constructions.

In fact, composite sheet piles pioneers expect that market forces related to these three factors will soon spike greater interest in composites. Significant growth in the population of marine borers (who do to wood in water what termites do to wood on land) and strict restrictions on the use of toxic waterproofing treatments have made wood pilings less desirable. Likewise, bans on lead-based primers, sandblasting and solvent-based paints have made it progressively more difficult to protect waterfront steel from rust, particularly in seawater environments. Maintenance and replacement costs for deteriorated wood, concrete and steel piling systems are now pegged at more than $1 billion (USD) annually in the U.S. alone, according to the Army Corps. of Engineers (UACE) — a factor expected to put composites in a more favorable position as the material of choice for those far-sighted enough to want to avoid chronic maintenance.

Indeed, composite sheet piles options — corrugated or otherwise profiled panels, often with vertically interlocking edges used to assemble wall-like structures — are opening new channels to applications previously dominated by steel. Similarly, ccomposite sheet piles (filled or hollow cylindrical tubes) have begun to carve out a significant niche in fendering applications and continue to replace traditional materials in waterfront restoration projects. Additionally, GFRP wraps are becoming commonplace as an in-situ repair technique for concrete, wood and steel piles.

Kristofer Grimnes, development manager at Harbor Technologies (Brunswick, Maine), a manufacturer of glass fiber-reinforced round piles, sees fair weather ahead. “It will just take time,” he notes. And like many of his counterparts, Grimnes is relying on word of present successes to clear up any misconceptions about composite sheet piles products and help piling suppliers navigate future competitive waters in this marine niche. “With every success,” he says, “comes a new opportunity.”

This article comes from compositesworld edit released