TMT bar or Thermo Mechanically Treated bar is one of the most popular reinforcement bars used for the construction of houses, multi-storeyed high rise, bridges, flyovers and other civil engineering structures and known for its excellent tensile strength, durability, and ductility. TMT bars are the safest option for construction, as they are highly resistant to earthquakes.
The manufacturing process of TMT bars is called Thermo Mechanical Treatment. Iron scrap is an important raw material in this process. The Iron scrap is melted in an electric furnace and then cast in a casting machine into rectangular shape Billets. Now, these Billets pass through various polishing and rolling processes above the recrystallization temperature to get the required size and shape. This process is called Hot Rolling Process.
The Hot rolled steel bars undergo a specially designed water cooling system called quenching. Quenching hardens the outer surface of the bar while the inner core remains relatively higher temperature, forming a soft and ductile inner core. The variation in the microstructure of the steel bar due to the temperature difference between the outer and inner core provides huge strength to the bar.
TMT Steel Prices
TMT steel prices are lower compared to the conventional bar prices. TMT steel bars offer much greater structure with the same amount of the steel. This drastically brings down TMT steel price and its production cost. Hence the TMT steel price in the market is much lower. TMT Bars are considered one of the best technologies in the construction industries because of their affordable prices. Availability of Grades Fe-550D results in steel Saving of 14 – 19%
Here’s a note of some of the Applications of TMT bars:
The best part of preferring TMT bars over other conventional bars is they offer longevity and robustness to any concrete structure. TMT bars are widely applied in different spheres in the construction field.
1) High rise buildings
2) Bridges
3) Flyovers and Dams
4) Underground structures
5) Can be Recycled without compromising on quality
Important Features of TMT bars:
Strength: The High strength TMT bars are stronger than the conventional bars and gives much greater concrete structure.
Corrosion and thermal resistant: TMT bars are highly resistant to corrosion. The problem with the conventional construction of the iron rods and concrete slabs is that iron rods will soon begin to rust very early. Where as TMT bar show negligible rusting in comparison to conventional bar due to its advanced manufacturing technology.The Thermal stability of the TMT bars is high making them safe from any fire accidents. Hence TMT bars have longer and safer life than concrete structure.
Flexibility and elongation property:
TMT bars are incredibly flexible and have amazing bending capacity. TMT bars have a great degree of elasticity and can be moulded into any shape.The most unique feature of TMT bars include higher elongation. This makes it bendable and flexible making it safe from natural calamities like earthquakes. TMt bar can elongate upto 50% more than its original length. Hence due to its flexibility, bending and elongation property TMT bars are used for a wide range of construction purposes.
Chemical composition of TMT bars:
| Chemical | BIS (Bureau of Indian Standards) |
| Carbon (Max%) | 0.30 |
| Manganese (%) | 0.5 to 1.2 |
| Sulphur (%) | 0.06 |
| Phosphorous (%) | 0.055 |
Physical Properties of TMT bars:
| Tensile Strength (Min.) | 485 N/mm2 |
| Elongation (Min) | 14.50% |
| Proof Stress (Min.) | 415 N/mm2 |