Deformed bar is a common term used within the construction industry. The name of the steel bar is derived from the deformed pattern that can be noticed on the surface of the bar. These steel bars come with different deformation patterns which are critical for reinforcing structural elements during construction.

What are deformed bars?

Deformed bars are steel bars distinguished by a ribbed rough surface on the bar. This deforming helps increase bonding between reinforcement and concrete and to maintain friction between them. Deformed bars are commonly called steel rebars or steel reinforcement bars.

According to the revised guidelines of Central Public Works Department for the use of reinforcement steel in structures, “The reinforcement steel of any RCC (Reinforced Cement Concrete) structure shall confirm to the provision of IS 1786:2008 Indian Standard Specification for high strength deformed steel bars and wires for concrete reinforcement.”

To understand this, you must first learn the meaning of reinforcement steel. Steel bars and wires that are used to strengthen and support concrete in buildings are called steel reinforcement.

Therefore, the CPWD revised guideline means that all the steel bars and wires that are put inside concrete structures to add to the load bearing capacity of the structure must adhere IS 1786:2008 Indian Standard Specification for high strength deformed steel bars and wires for concrete reinforcement.

Types of deformed bars

There are different types of deformed bars:

• Hot rolled deformed bars

Hot rolled deformed bars are popularly known as Thermo Mechanically Treated bars or TMT bars. They are used to build RCC structures. These rebars are commonly used for their superior tensile strength.

• Twisted steel bars

Twisted steel bars are made by spinning up to 7 wires together into a strand. The twisting process of the steel bars enhances their strength and ductility, making them more resistant to bending and breaking under heavy loads. These are typically used as supports of frameworks for prestressing RCCs.

Most popular twisted bars in India are cold twisted deformed bars. Also called TOR steel in India, it is made by cooling hot steel obtained from the furnace at ambient temperature and then stretching and twisting it to increase yield strength.

Benefits of deformed bars

IS code has mandated the use of deformed bars in RCC structures as they provide the necessary strength and durability. Deformed bars have many advantages in the construction industry:

• These bars contribute to the ductility of the structure, allowing it to withstand minor movements and deformations. This is crucial in seismic regions where buildings need to absorb energy during earthquakes.
• Reformed bars help control cracks that occur in concrete structures. They prevent cracks from spreading by holding the concrete together.
• These steel bars help in distributing the load more effectively within the concrete structure. Enhancing the load carrying capacity without the building experiencing significant deformations or failures.
• The deformed patterns on the surface of these steel bars help create a mechanical box. And with the concrete. This ensures that the concrete and the bar together resist tensile and shear forces, improving the structural integrity of the building.

While deformed bars have many advantages, they have some disadvantages as well. Deformed bars disadvantages include difficulty in welding due to the deformations on the surface. This creates irregularities and hinders the welding process. Special tools and equipment are required for cutting and bending these bars.

Sizes of deformed bars

Deformed steel bar sizes produced by manufacturers in India includes 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 32mm, 40mm, 45mm and 50mm. These are common sizes available with Indian steel manufacturers.

Grades of deformed bars

Deformed bars grade adheres to IS 1786:2008. given below are the grades of high strength deformed bars and wires that should be used for concrete reinforcement in construction:

Fe 415, Fe 415D, Fe 415S

Fe 500, Fe 500D, Fe 500S

Fe 550, Fe 550D

Fe 600

Deformed steel bar prices

There are many manufacturers in India selling deformed bars. Have a look a few manufacturers and their deformed bar prices:

• Kiran Infra Ispat Limited – Round deformed bar – ₹56/kg
• KLG Ecolite – Round deformed bar – ₹ 54/ Tonne
• Shree Ji Steel Corporation – Round deformed bar – ₹ 46/ Kg
• Sri Kirthika International – High strength deformed bar – ₹ 64000/ Metric Tonne
• Sri Rishika Steel Suppliers – TMX 500 deformed bar – ₹ 65000/Tonne

Source: Indiamart

Uses and applications

There are many use cases of deformed bars in the construction industry. Deformed bars are used for:

• Reinforcing concrete columns
• Reinforcing concrete beams
• Building concrete slabs, such as floor slabs and roof slabs
• Building concrete foundations
• Reinforcing retaining walls
• Building superstructures and substructures during bridge construction
• Construction of hydraulic structures

Deformed bars are widely used in the Indian construction industry. Their applications depend on the project design and requirements. They immensely contribute to the strength and durability of buildings and other complex infrastructure projects. Thus, they make a fundamental raw material for the construction industry.

Also read: GST on steel bars: Tax on steel, iron and TMT steel bars in India

Author: Priyanka Babu

Priyanka is a seasoned content marketing professional with more than 6 years of experience crafting various forms of business and technology sector content. Her insightful writing tackles critical issues faced by small-scale manufacturing businesses. Priyanka’s clear and concise communication empowers businesses to make informed decisions and thrive in today’s dynamic business environment.