Sustainable Piling

There has been increasing interest in the use of recycled polymer composites as a replacement for timber piling in coastal and waterfront environments. This trend is expected to grow because polymeric piling is more attractive than timber when life cycle costs are factored in, and also because polymeric piling is a creative method for the recycling and reuse of tons of plastic waste. However, composites face obstacles because they do not have a long track record of use in civil engineering structures. Polymeric piling is typically made of high density polyethylene (HDPE) and reinforced with fiber reinforced polymer E-glass (FRP) or steel. This project summarizes the current state of the art in polymeric piling practice.

Reinforced Plastic Piling:

  • Extruded HDPE matrix
  • Fiberglass or Steel structural Reinforcement (6–16 bars)
  • Additives & Foaming Agent
  • D = 25–40 cm
  • L = 23 m
  • 2 Manufacturers

Environmental Advantages of Fibre-Reinforced Plastic (FRP)

  • Utilize Recycled Materials
  • 3 million tons of rigid plastic containers are produced   each year
  • 75% are land-filled
  • Eliminates Creosote & CCA
  • Disposal problems
  • Threat to marine life
  • Potential health hazard to workers
  • Preserves Old Growth Forests

State of Polymeric Piling Practice

  • A few vendors
  • Prototype in Los Angeles in 1987
  • Material Cost = 2–3 conventional systems (~Foundation cost  = 120% of conventional piling)
  • Primarily used to resist ship impact (fendering)
  • Made of recycled HDPE with E-glass or steel reinforcement
  • Additives and stabilizers to improve performance

Designer Concerns Delaying Adoption of Polymeric Piling 

  • Lack of long-term record
  • Creep
  • Cost
  • Durability