What Is Fibre-Reinforced Concrete?

Fibre-reinforced concrete is a type of concrete mix that contains fibrous materials like synthetic or natural fibres or glass fibres. It comprises cement, aggregate, and discrete – short fibres distributed uniformly throughout the composite material.

Adding fibres to concrete reduces cracking and increases overall energy absorption and structural integrity. However, the fibres are no substitute for stainless steel-reinforced concrete because they do not improve flexural strength or the ability of concrete to bend without breaking.

Types and applications of fibre-reinforced concrete

Fibre reinforcement is used in regular and shotcrete concrete – a type of concrete that can be sprayed.

• The most common type of steel fibre used in fibre-reinforced concrete is round-shaped steel fibres. Steel fibre in concrete is frequently used in road pavement overlays, bridge decks, and airport pavement.
• Glass fibres in concrete can make lighter, more modern structures like furniture or architectural claddings for buildings.
• In concrete, synthetic fibre is made up of one of two types of fibres: microfibres or macrofibres. Microfibres are commonly used in concrete to reduce shrinkage cracks and are made of acrylic, polyester, nylon, or polypropylene, among other materials. On the other hand, macrofibre is a more cost-effective reinforcement alternative to welded wire in concrete structures that require high tensile strength. As a result, microfibres are commonly used in constructing sidewalks, curbs, and driveways, whereas macrofibres are widely used in constructing septic tanks and manholes.

How is fibre-reinforced concrete mixed?

Fibre-reinforced concrete can be made with either regular mixed concrete or mortar, provided the fibres are evenly distributed throughout. When mixing fibre-reinforced concrete, the water-to-cement ratio and fibre size, or the aspect ratio, which is the length of the fibre divided by the diameter, must be considered.

The percentage of fibre used in the concrete is crucial because the volume of fibre used can affect the structure’s strength and sturdiness. When mixing fibre-reinforced concrete, it should be done in a uniform and segregated manner. Fibres should be mixed in before adding the water, so they are evenly distributed and do not ball up. Fortunately, you can leave this to the experts at Eastern Readymix, who will supply ready-to-use fibre-reinforced concrete directly to your site.

Benefits of fibre-reinforced concrete

Compared to regular concrete or reinforcing concrete with steel rebar, using fibre-reinforced concrete on a construction project has a few distinct advantages.

• Early crack prevention. Fibres help to control shrinkage cracking as the moisture level in the concrete mix changes as water evaporates. Fibre-reinforced concrete prevents or greatly reduces early cracking from the start.
• Durability and strength. Compared to unreinforced concrete, adding fibre increases the concrete’s overall durability, helps lower corrosion levels and cavitation damage and has a higher tensile strength.
• Increased ductility. Fibre-reinforced concrete is less likely to be damaged by high tensile stress and can increase the weight a structure can support, particularly when microfibres are used.
• A non-rebar alternative. Fibres can be used as an alternative reinforcement material to steel rebar or added to steel-reinforced concrete to reduce the amount of steel required, depending on the structure. This could also help to reduce the overall cost of the project.

Contact Eastern Readymix Tshwane for details

Eastern Readymix Tshwane offers ready-to-use standard and pumpable concrete designed for all general applications. Our standard and pumpable concrete mixes can be created and supplied to the client’s specifications, including fibre-reinforced concrete. Contact one of our representatives today for more information about our fibre-reinforced concrete.