[This poster won 2nd prize at the 2018 ICOE Poster Awards]

ABSTRACT
Reinforced concrete (RC) is well suited for the offshore environment, with good strength and stiffness properties at a low unit cost. However, there are a number of issues with using the material in its conventual form for floating structures.

• Concrete is heavy, with minimum wall thicknesses driven by the practicality at fitting in internal steel rebar with adequate cover to ensure durability - can be an issue for floating structures;
• Concrete cracks under tension - reduced permeability of cracked concrete can be an issue for reinforcement durability and watertightness. Additional prestressing is often required to keep structure in compression.
• Dynamic, multi-axial force regimes result in complex internal reinforcement requirements; rebar is a high cost item for RC structures.
• Complex shapes require complex formwork; also, a high cost item.