Fibre Reinforced Concrete (FRC) is a special kind of concrete composed of cement aggregates, mortar or concrete, and a certain type of fibres. Fibres are added to improve tensile strength, increase durability, and increase its structural integrity. Fibres also control cracking caused by drying or plastic shrinkage and reduce the permeability of concrete, preventing the bleeding of water.
Fibres used in reinforced concrete are natural fibres, synthetic fibres (plastic), glass fibres, and steel fibres. The properties of fibre-reinforced concrete can be altered by changing certain aspects, including the geometric configuration, direction, dispersal, concentration patterns, type, and quantity of fibres.
The properties of fibre-reinforced concrete depend upon many factors, including:
- Water- cement ratio
- Concentration or dispersal of the fibre
- The volume proportion of the fibre
- The length and diameter of the fibre
- The type of fibre used
What Are the Different Types of Fibre-Reinforced Concrete?
There are many types of fibre-reinforced concrete available in a variety of shapes and sizes. Here are the most common ones:
Polypropylene (PP) Fibre-Reinforced Concrete
Polypropylene fibres are a type of synthetic fibre made from propane and used in various applications. They enhance abrasion- and impact resistance and improve concrete mix cohesion, enhancing permeability across long distances.
Polypropylene fibre can improve ductility and boost resistance to plastic shrinkage when curing. Polypropylene has heat-insulating characteristics and is highly resistant to alkalis, organic solvents, and acids.
Polyacryonitrile (PAN) Fibre-Reinforced Concrete
Polyacryonitrile (PAN) Fibres, also known as polyvinyl cyanide and Creslan 61, are made of synthetic, semicrystalline organic polymer resin. PAN fibers are the chemical precursor of very high-quality carbon fiber. They improve the toughness of concrete and absorb fracture energy during the crack propagation process. Adding 1.0 % volume PAN fibers to concrete have been shown to improve impact toughness by up to 250%.
Polyethylene (PE) Fibre-Reinforced Concrete
Polyethylene fibres are used to reinforce concrete and improve ductility, toughness and elasticity. They are more durable than steel fibres as they do not rust over time. Polyethylene fibres increase compressive strength, flexural strength as well as tensile strength. They are very light, can float in water and are therefore used in lightweight concrete projects.
Polyvinyl alcohol (PVA) Fibre-Reinforced Concrete
PVA fibers have high tensile strength and can also be used for shrinkage control. While they cannot replace reinforcing steel, they improve the mechanical properties of cured concrete, boosting its strength. When stress is applied, these fibres increase ductility by micro-fracturing, allowing the concrete to bend, not crack. They are also the best choice for hidden fibres, as they will not show or stick out after the surface has been ground. PVA fibres, however, can be difficult to formulate and can be more expensive.
Steel Fibre-Reinforced Concrete
Steel fibre-reinforced concrete (SFRC) is a metal reinforcement that can bring significant qualitative changes to the concrete’s physical characteristics. It reduces steel reinforcement requirements, controls cracks widths, and holds the crack widths tightly, enhancing durability. Steel fibre can also improve structural integrity and increase resistance to impact, bending, fatigue, cracking, and specific strength (tenacity).
SFRC has been widely used in major structures like housing, heavy-duty pavement, flooring, mining, and bridges to improve strength, stress resistance, toughness, and long-term behaviour.
Glass Fibre-Reinforced Concrete
Glass fibre-reinforced concrete (GFRC) is made of several fine filaments bonded together to form a strand. GFRC is cheaper, less brittle, and allows reduced bleeding, permeability, and formation of micro cracks. It provides increased durability, high tensile strength, improved flexural strength, minimum weathering effect, and reduced deflection.
They are resistant to the alkali-silica reaction (ASR) by using zirconia and are commonly known as alkali-resistant glass fibres. They can be used for both plastic shrinkage control and reinforcement at the same time, by using a mix of shorter and longer fibres. The typical (and minimum) GFRC volume fraction dose is 3 – 6% of Cement content (ie: 10-15kg per cubic meter).
Glass fibres also add a decorative effect because they are visible on concrete surfaces. GFRC is commonly used to manufacture precast products like wall cladding and spun pipes.
Natural Fibre-Reinforced Concrete
Natural fibres are directly extracted from a mineral source, an animal, or vegetables. While they are primarily used in fibrous materials like cotton, grains, and wood, natural fibres have also become popular in making concrete because they are plentiful and locally available. Some examples of natural fibres include coir, jute, vegetables, rice, flax, coconut and cashew nut shells.
Contact Bisley Today
If you’re searching for a reliable fibre supplier for fibre-reinforced concrete, search no further than Bisley. Our sales representative can help you choose the best fibre option suitable for your application. Contact us today for inquiries and learn more about our fibre products.