Fibre-reinforced concrete has fibrous materials uniformly distributed and randomly oriented throughout its volume. Before discussing the advantages of fibre-reinforced concrete, we first need to describe the different types. Fibre-reinforced concrete has distinct advantages and disadvantages, depending on the types of fibres used. By adding fibres to a concrete mix, we imbue the mix with some of the fibres’ properties. Bisley supplies building materials to the construction sector worldwide.
Types of Fibre-Reinforced Concrete
We give a breakdown of the different types of fibre-reinforced concrete below.
Steel Fibre-Reinforced Concrete (SFRC)
You can use different variations of steel fibres for concrete reinforcement. SFRC is used for applications like warehouses, runways, parking lots and container storage yards. Its flexural strength and durability and reduced permeability make it ideal for tunnel construction.
Polypropylene Fibre-Reinforced Concrete
Polypropylene fibre is a synthetic fibre derived from propylene gas. It’s heat resistant and is resistant to acids, alkalis and solvents. It’s mainly used to reduce cracking caused by drying shrinkage.
Carbon Fibre-Reinforced Concrete
Carbon fibres have a high strength to weight ratio but are brittle. Composite materials usually have a carbon fibre component to take advantage of this fibre’s strength, chemical resistance and heat tolerance.
Glass Fibre-Reinforced Concrete
Glass fibre consists of fine fibres of glass. It has roughly the same mechanical properties as the other fibres. Glass fibre is cheaper than carbon fibre and less brittle in composite material.
Synthetic Fibre-Reinforced Concrete
Macro synthetic fibres were initially developed for use in sprayed concrete. These blended polymers resistance to staining and spalling make them ideal for use in marine environments. Micro synthetic fibres give good resistance to plastic shrinkage.
Natural Fibre-Reinforced Concrete
Natural fibres in concrete is not a new concept. Natural fibres such as coir, horsehair or straw were arguably the first form of fibre-reinforcement used in concrete.
Advantages Of Fibre-Reinforced Concrete
- Added tensile strength in all directions
- Reduced fire damage
- Increased strength after cracking as fibres bridge the gap between cracks
- Reduced drying shrinkage and plastic shrinkage
- Lower maintenance
- Reduced thickness of the slabs
- More flexibility in a joint placement
- Higher load-bearing capacity
- Reduced permeability
Disadvantages
- Fibres may stick up out of the surface
- Balling of fibres may occur, resulting in uneven strength
- 10-15% increase in the cost of the concrete
- Reduced workability
- Some fibre types make the concrete heavier
Conclusion
Fibre-reinforced concrete has many advantages and a few disadvantages. The composition of the fibres in concrete also change the properties of the pour, so using fibre-reinforced concrete gives you some flexibility. The most commonly used reinforcements have advantages like reduced cracking from shrinkages, added strength and higher load-bearing capacity. Synthetic reinforcing fibres in concrete have uses in marine environments and other extreme conditions. Glass fibres give strength without carbon’s brittleness. Concrete reinforcement often uses composite fibres to take advantage of different properties of materials that combine well. Bridges, tunnels and dams all make use of fibre-reinforced concrete in their construction.