Combating flood risks with composites

Flooding is the most destructive natural disaster worldwide, causing over 250,000 fatalities and $1 trillion in damages over the past 50 years, accounting for 40 per cent of all losses from natural catastrophes. Here Lauri Turunen , our senior manager for application engineering, examines how sheet piling materials like steel and PVC cannot tackle all the challenges posed by harsh environments, and how pultruded composites offer a robust, corrosion-resistant alternative.?

Sheet piles are essential in construction, commonly used for retaining walls, flood defenses and erosion control. They provide stability by preventing soil movement and water ingress, playing a crucial role in infrastructure projects. Understanding their material composition and associated challenges is key to effective construction.?

Challenges of traditional sheet pile materials?

Traditionally, sheet piles are made from steel and PVC. Steel, while strong, is vulnerable to corrosion, especially in marine environments where saltwater accelerates rusting. For example, in coastal areas, steel sheet piles can lose structural integrity over time and require consistent maintenance, adding to overall costs.??

Beyond corrosion, steel’s weight presents significant challenges. Heavier sheet piles require larger machinery for transportation and installation, driving up labor and handling costs. This adds complexity to projects, particularly in remote or difficult-to-access locations.?

Polyvinyl chloride (PVC), introduced as a corrosion-resistant alternative, is lighter than steel, making handling and installation easier. However, it has limitations in stiffness and long-term durability, which can impact performance in demanding environments.??

The advantages of pultruded FRP composites in sheet piling?

Composite materials, particularly fiber-reinforced polymer (FRP) composites offer an invaluable alternative for extreme applications such as those in coastal or industrial settings. Exel produces advanced FRP sheet piles made from E-glass fibers and thermoset resins. These materials provide exceptional corrosion resistance, ensuring longevity even in challenging environments. Unlike steel, which deteriorates in saline conditions, or wood that decays in moisture, our FRP composite sheet piles remain unaffected by such environmental factors.?

Although initial costs may be higher for FRP, its lightweight nature reduces transportation and handling expenses. Combined with its long-term durability, this can lead to substantial savings over the lifespan of a project. With fewer maintenance requirements and a significantly extended service life compared to traditional materials, FRP proves to be a cost-effective investment.?

FRP composites excel in harsh environments, resisting degradation from saltwater and harsh chemicals while maintaining structural integrity, even under extreme temperatures. The versatility of FRP also allows for different surface finishes and colors, providing greater aesthetic flexibility than steel, which require coatings that will degrade over time and require periodic maintenance.?

FRP’s lightweight properties make handling and installation simpler, reducing both labor costs and logistical challenges. With tensile strengths reaching several hundred to over a thousand MPa — well above PVC’s typical sub-hundred MPa range — FRP offers superior resistance and reliability for demanding environments. Additionally, FRP can be customized to meet specific structural needs, providing flexibility that PVC lacks.?

Exel's FRP sheet piles exhibit high tensile strength and stiffness, ensuring durability even under significant loads. Manufactured using a continuous pultrusion process, which draws E-glass fibers through a resin bath, these piles achieve a uniform cross-section, enhancing both strength and corrosion resistance.?

As the risk of flooding remains critical, resilient infrastructure is essential. FRP sheet piles represent a robust solution for challenging environments. To learn more about how composites can benefit your project, get in touch with our team here.