The history of steel bars and the emergence of TMT bars in world and in India!
Before World War 2, Mild Steel (MS) bars wererecognized as the optimum bars, used in building concrete structures. As World War 2 ended, emergence of technologies and innovations resulted in CTD – Cold Twisted Deformed bars. Even though the composition of the CTD remained the same as MS bars, it had a higher strength than MS bars. It was assumed that the strength of CTD was 60% more than that of MS bars.
As the technology developed even more, innovations in the steel industry were inevitable. One such innovation resulted in the development of TMT Steel bars, Thermo Mechanically Treated Steel Bars. These steel bars were so optimum that they are the first choice of steel bars for the construction industry even today. In 1979, the TMT bars came in the grades Fe 415 and Fe 500.
In India, the TMT steel bars were introduced in 1985 and the grade of TMT bars used were Fe 500 to Fe 550. The characteristics of the steel bar such as bendability, flexibility, weldability and ductility played a significant role in increasing the trust of the construction sector on the bar, around the world and India.
The development of TMT bars only meant that the demand for CTD and MS bars would decrease and the use of TMT bars started to get deeply into the construction industry.
The Use of TMT Bars in India!In India, since the introduction of TMT steel bars, no other steel bar has been able to sustain its presence in the market. TMT steel bars have certainly become the perfect choice for the construction industry. Invariably, the TMT steel bars are used for most of the construction projects in India ranging from construction of dams, bridges, thermal and hydel power plants, industrial structures, high-rise buildings, underground platforms in metro railway and rapid transport system.
As we know, TMT steel bars come at different grades, hence are used according to the scale and size of the concrete structure. Essentially, Fe 500D grade TMT bars are used due to its balance in strength and flexibility.
The TMT bars do not only vary in grades but also vary in thickness. The thickness of the bars also contributes towards their use, as the steel bars with greater thickness will be used for huge construction sites such as dams, bridges, power plants, while the TMT bars with lower thickness will be used for the construction of corporate buildings and residential buildings.
TMT bars are widely used in earthquake prone areas and corrosion prone areas as well, due to its capability to hold in the ground, even at the times of natural calamity.
One more important feature which helps the construction industry to blindly trust TMT steel bars is its fire resistance ability. The TMT bars can absorb heat up to 600 degrees Celsius. It is a well-known fact that many buildings around the world collapse due to fire accidents and having a steel bar which is fire resistant reduces the risk of the building getting collapsed.
In conclusion, I would like to say that, the emergence of TMT steel bars has definitely solved more than one problem of the construction industry. Not only solving problem, but the bars have also successfully gained the trust of the industry. Kalinga TMT from Hyderabad, also has given a good platform for TMT steel bars to grow, especially in the South of India, blossoming the construction industry to another level.