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Why composite materials are used

Short answer

Composites combine matrix and reinforcement to give high strength-to-weight ratio, tailored properties, corrosion resistance, and combined advantages (e.g., RCC). They provide uniform quality, low maintenance, and replace scarce natural materials, though initial cost can be higher.

Why is the use of composite materials so high (predominant compared with conventional natural building materials)?

A composite material is made by combining two or more different materials (a matrix and a reinforcement) so that the product has better properties than any of the components. Examples: reinforced concrete, FRP, GRP, plywood, fibre cement, steel-concrete composite.

Reasons for their predominant use

  1. High strength-to-weight ratio: Fibres (glass, carbon) in resin give strength like steel at a fraction of the weight.
  2. Tailor-made properties: Fibres, matrix and layout can be chosen to give the needed strength, stiffness or insulation.
  3. Durability: They do not rust or rot, and resist chemicals and weather better than steel and timber.
  4. Combines advantages: Concrete resists compression and steel resists tension in RCC.
  5. Easily moulded: Complex shapes and large components are made by moulding and cast-in-place.
  6. Low maintenance and long life.
  7. Natural materials are scarce: Good timber and stone are limited, expensive and uneven in quality, whereas composites are uniform and consistent.
  8. Better thermal, acoustic and fire performance in several kinds (e.g. sandwich panels).

Limit: They may cost more at first, and some (FRP) cannot be easily recycled or repaired.

✓ Answer checked by Claude Opus 5.5 (high effort)

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