Although India’s IS:1786 building codes specify only Fe-415 for reinforced cement concrete, its usage is declining as the market is shifting to higher grades. The construction industry has started adopting newer grades like Fe500, Fe550, and Fe500-D.
Higher value-added products like corrosion-resistant steel bars, epoxy-coated, earthquake-resistant and galvanised rebars are making their mark in India’s fast-growing TMT bar market. TMT bars with 8mm and 25mm are being used in infrastructure projects, buildings, bridges and highways. With an estimated demand of around 40 million tonnes, manufacturers are envisaging excellent growth in the coming decade.
Demand for better quality products
The Indian market has several regional players serving local customers and their acceptance among consumers is good, resulting in high business volumes in the regional markets. Global consultancy Frost & Sullivan forecasts India’s demand for rebars to hit 41.82 MnT by 2020-21.
In recent times, TMT bars have become the chosen product for discerning builders, thanks to their excellent bonding with cement, superior weldability, excellent bendability and corrosion, fire and earthquake resistance qualities. Particularly in humid climate zones where the metal is prone to corrosion, TMT steel bars are seeing much demand.
Producers like Tata Steel, SAIL, Vizag Steel, Jindal Steel and Power Limited and JSW Steel account for a sizeable chunk of the rebars market, although a major share has been grabbed by regional manufacturers including Radha TMT – a reliable brand based in South India. Radha TMT is set to become a national brand shortly.
Stringent quality testing, a key in-house requirement
The BIS certification scheme requires a laboratory to be maintained by all manufacturing units. These should be suitably equipped with facilities where different tests can be carried out in accordance with proposed methods. The tests ascertain the levels of carbon, manganese, sulphur and phosphorous through chemical testing.
Advantages of TMT technology
Thermo Mechanical Treatment is a simultaneous application to steel that involves heating and cooling. The process develops better properties in steel by refining its micro structure and ensure durability, ductility and strength. The process developed has many advantages.
- TMT bars have a special rib design that enhances their quality and bonding with cement.
- Having a high elongation point, the bars are earthquake-resistant and can easily elongate without compromising their actual measurement or quality. Elongation is a TMT bar’s ability to elongate or deform before it is damaged. Greater the elongation, stronger the building.
- They are highly flexible or ductile – the soft ferrite-pearlite core of the bars gives superior bendability ensuring that they can be easily bent and moulded.
- TMT bars are highly ductile and have a super-strong surface layer which help TMT bars withstand fatigue for long.
- TMT bars are much stronger than conventional steel bars and can give up to 20% stronger concrete structure with the same amount of steel.
- TMT bars are corrosion resistant. In sites where the TMT bars are exposed to water and moisture for long, the anti-corrosive properties of TMT bars extend their lifespan and ensures safety of the structures
- The superior weldability of TMT bars encourages architects and designers to build innovative, aesthetic structures without compromising on quality.