What is Fiber and How it is Used as a Construction Material ?

Fiber or fibers is a class of material which are having continuous filaments or having discrete elongated pieces similar to the length of thread. Fibers are very important in the biology of plants and animals for holding tissue together. They are often used in the manufacture of other materials. Fibers can be spun into filaments or string or rope which can be used as a component of composite material or matted into sheets so as to make the products like paper or felt. Fibers are inorganic or organic, natural or synthetic. Synthetic fibers can be produced very cheaply and in large amounts as compared to natural fibers. Rayon and nylon are organic synthetic fibers.Burlap is a coarse jute or hemp which is a natural fiber. Hessian is a jute fabric. Silk and cotton are produced from natural fibers. Glass wool, lead wool and asbestos are mineral fibers of which glass wool and lead wool are synthetic fibers. Steel fiber, carbon fiber and glass fiber are the new and recent trends used in the construction work.

General Uses of Fibers

• Fibers are used for packing and making fabrics and felts.
• Glass wool made of very fine fibers of glass is used for making acid-proof and fire-proof fabrics.
• Glass wool is also used as a packing material for heat, sound and electric insulation. It is commonly used in a solar water system.
• Lead wool prepared from fine fibers of lead is used in water pipe joints to stop leakage of water. Natural jute fibers are extensively used in plumbing work to stop leakage of water.

Types of Fibers :

There are mainly three types of fibers which are commonly used as a construction materials.

1. Steel fiber

Steel fiber are made from the cold drawn steel wire with low content of carbon or stainless steel
wire. They are manufactured in various types such as hooked steel fibers, undulated or flat steel fibers according to the need required in the construction project. These fibers are used in the construction for concrete reinforcement. Steel fiber reinforced concrete is less expensive than hand tied re-bar shape, dimensions and length of the fiber are more important because it increases the tensile strength of the concrete.

Steel fibers can only be used on surfaces so as to avoid corrosion and rust stains. Fiber-reinforced normal concrete is mostly used for on-ground floors and pavements and also used for the construction parts such as beams, pillars, foundation etc.

Properties of Steel Fibers

• It increases the tensile strength of concrete.
• It is more tough and hard.
• It avoids corrosion and rust stains.
• They are more elastic in nature.
• Steel fibers are available with standards as ASTM 820/96, ASTMC 1116/95 and DIN 1045.
• It has a tensile strength of 1.100 N/mm².
• They are available in the shapes like flat, hooked and undulated.

Applications of Steel Fibers on Field

• Steel fibers are highly used in tunnel lining work.
• It is mostly used in the construction of airport runways and highway pavements.
• Most commonly used in precast concrete so as to increase the tensile strength.
• They are used in shotcrete.
• Used in the construction of parking.
• It is used in anti-seismic buildings.

2. Carbon fibers

Carbon fiber is a material consisting of extremely thin fibers about 0.005 mm to 0.010 mm in diameter and mostly composed of carbon atoms. Carbon fiber is alternately called graphite fiber. The carbon atoms are bonded together in microscopic crystals which are more or less aligned parallel to the long axis of the fiber. The crystal alignment makes size of fiber more strong. Number of carbon fibers are twisted together so as to form a Yarn which can be used as it exist or woven into a fabric.
It can be combined with a plastic resin and wound or moulded to form composite materials like carbon fiber reinforced plastic to provide a high strength to weight ratio of the materials. The atomic structure of carbon fiber is similar to that of graphite consisting of sheets of carbon atoms arranged in a regular hexagonal pattern. Carbon fibers shows the number of properties very close to the properties of asbestos. Each carbon filament thread is a bundle of many thousand carbon filaments. A single such filament is a thin tube with a diameter of 5-8 μm (i.e. 5-8 micrometers) and consists of almost exclusively of carbon.

Properties of Carbon Fibers

• It has a high tensile strength, low weight and low thermal expansion.
• They are rigid materials which are resistant to stretching and compression.
• It is chemically inert or unreactive materials.
• They are resistant to corrosion.
• Fibers contained about 85% carbon has excellent flexural strength.

Application of Carbon Fibers

• Carbon fiber is mostly used to reinforce composite material.
• Reinforced Carbon-Carbon (RCC) consists of carbon fiber-reinforced graphite and is used structurally in high temperature applications.
• It increases the tensile as well as compressive strength of concrete.
• Due to high tensile strength, low weight and low thermal expansion it makes the carbon fiber very popular in aerospace, military and motersports along with other competition sports.
• Carbon fiber is extensively used in the bicycle industry, especially for high-performance racing bikes.
• It is also used in some tennis rackets.
• It is now being used in musical instruments for its weather resilience and ability to recreate the tone of guitars.

3. Glass fibers

It is also called as fiber glass. Glass fiber is the material made from extremely fine fibers of glass. It was invented in 1938 by Russell Games Slayter. In 1893, Edward Drummond Libbey exhibited a dress at the World’s Calumbian Exposition incorporating glass fibers with the diameter and texture of silk fibers. This was first worn by the well known and popular stage actress of the time Georgia Cayvan. There are two main types of glass fiber manufacture and two main types of glass fiber product. First fiber is made either from a direct melt process or a marble remelt process. Both start with the raw materials in solid form.It is almost and always mode of platinum alloyed with rhodium for better durability. Platinum is used because the glass melt has a natural affinity for wetting it. The fresh and thin fibers are more strong because the thinner fibers are more ductile.

Properties of Glass Fibers

• It has high ratio of surface area to weight.
• They have good thermal insulation.
• It has a good tensile strength but has no strength against compression.
• Compressive strength is weak but can be increased by reinforcing it with plastic.
• When the glass fiber is reinforced with plastic, then reinforced material can resists both compressive and tensile forces as well.
• It is resistant to chemical attack. However, if its surface area is increased, then it makes them more susceptible to chemical attack.
• They are corrosion resistant.

Application of Glass Fibers

• Corrugated fiber glass panels are widely used for outdoor canopy or greenhouse construction.
• It is used as a reinforcing agent for many polymer products like FRP and GRP which uses tubs, pipes for drinking water and ‘sewers, office plant containers and flat roof systems etc.
• It is reinforced with plastic material so as to increase tensile strength.
• Uses of regular fiber glass are mats, insulation, reinforcement sound absorption, heat resistance fabrics, corrosion resistant fabrics and high strength fabrics.
• Glass fiber reinforced plastics are used in the house building market for the production of roofing laminate, door surrounds, over-door canopies, window canopies and dormers, chimneys, coping system, heads with keystone and sill etc.
• The reinforced glass fiber with polymer and plastic is commonly used in fire water systems, cooling water systems, drinking water systems, sewage systems, waste water systems, gas system etc.