Being a contractor one must be aware of the materials being used in the construction of a structure. In the olden days, houses across India were built with concrete slabs and iron rods. The rods would begin to rust soon at a very early stage, that too, quite rapidly. It used to affect the stability of the structure in the long run, which would lead to a frequent repair of the house.
Structures made using cheap and inappropriate raw material can’t survive the wrath of nature. The most common cause of structural disasters involving bridges or large buildings is often poor planning, poor quality of material used and negligence on the part of the contractors. That’s why we can’t emphasise enough the importance of excellent quality TMT steel, which hold the concrete blocks together.
What’s a TMT bar?
TMT stands for Thermo Mechanically Treated. The TMT bars have a solid outer surface and a softer core. They are corrosion resistance and especially used for residential buildings, bridges, industrial establishment and all types of concrete reinforcement purposes. TMT Bars are much superior to conventional TOR steel bars by virtue of their multiple engineering properties.
Grade of the TMT bars
TMT bars are available in 4 different grades in India – Fe-415, Fe-500, Fe-550, and Fe-600. The greater the grade, the stronger the bar. Greater grade TMT bars should be used on floors and roofs of the building. Lower grade bars can be used in the construction of balcony railings and other decorative structures.
Integrated and secondary steel producers of India
Primary steel producers
The integrated steel producers are Jindal Steel & Power Limited, JSW Steel Ltd., Tata Steel, Rashtriya Ispat Nigam Limited (RINL), Steel Authority of India Limited (SAIL). Primary steel producers convert iron ore into steel. Everything from Iron Ore mines to Steel production is done at their premises. They produce crude steel of standard specification.
Secondary steel producers
They are the mini steel plants; they make steel by melting scrap or sponge iron, sometimes a mixture of both. Secondary steel is not prime with certifications, but it is still good for many types of uses. If your job doesn’t require mill certification secondary steel can be a good choice. Ispat Industries, Essar Steel, and Lloyd Steel are the largest secondary steel producers.
The difference between primary and secondary steel
Fe 415 and Fe 500D TMT rebars are recommended for residential construction purpose. Most of the contractors prefer Fe 500D because of its strength and ductility, which is very important because the bars will bend to a maximum extent before breaking. Primary producers use HYQST technique in order to form the right inner core which is flexible and outer core which is tough.
Secondary producers produce Fe 415 although many of the producers manufacture 500D as well. Secondary steel can be used to build flagpoles, fence posts, fence railings, poles for signs, bridge railings, culverts for roads etc. In secondary TMT rebars, there is generally no rib pattern, rib pattern helps in a strong bonding of cement.
All in all, TMT bars with high strength and corrosion resistance have made it possible for engineers across India to create structures they could not have imagined.