TMT Steel
Most people are particular about what cement or what paint to use when building a house, but don’t pay much attention to the brand quality of the steel bars, which really play a critical role in the strength and durability of the building.
The general outlook of Malayalees when building their house is that it should last for generations. Little wonder, they never compromise on its quality. They have a clear idea of what cement to be used or what paint they should apply on the interiors and the exteriors. On the other hand, when asked what steel bars would be used for the structure, the average homemaker is clueless about it. He would be uncertain about it and may say “ a steel bar of quality”.
The skeletal framework of TMT steel bars is actually the backbone of a house. It is instrumental in ensuring strength and support to the structure. All areas of the house should have steel bars of excellent quality. The cross beams of buildings should have the steel of 12 – 16 mm thickness. Since they bear heavy loads without support, such thick steel is required. In such instances, branded TMT steel bars of adequate thickness and length should be selected. It should also be ensured that the TMT steel bars we buy have ISI certification engraved on them.
When you compromise on the quality of steel due to ignorance or for immediate gains, remember that you are compromising on the safety and durability of your house. You would be setting apart almost 25% of the building cost on furnishings and other such decorative items. So when it comes to all the all-important steel bars, should you tighten your purse strings and go for a compromise? No, never! Because all other items can be replaced but the steel bars that go inside the concrete is in effect a lifetime investment.
Do not go for just a TMT….. go for the original TMT!
For the last several decades, people have never bothered about what kind of steel bars went into the concrete of their buildings. But now, people are aware that steel bars of varying qualities exist in the market, and each of them has various purposes.
Steel bars can be broadly divided into TMT (Thermo Mechanically Treated ) and CTD (Cold Twisted Deformed) bars. TMT bars are more suited for building construction as they are more strong, more durable, and more seismic resistant. People are now more or less aware of this fact. Engineers and architects insist to buy TMT steel bars for the building they construct. Hence, the demand for TMT steel bars has increased as never before. Now, they occupy a 97% share of the market.
When this demand for TMT steel rose, steel brands claiming to be TMT also increased. Many of them proved to be of spurious quality and had the single aim of robbing the buyer of his hard-earned money.
When the market got flooded with such fake brands, the customer became more vigilant and began to insist for reputed brands like ‘Metcon’. Mr. K.P.Joy (Pamba Steels, Kundannoor ) a TMT steel dealer endorses this and points out: “ It is always advisable to buy steel from reputed brands like Metcon. ”
Beware of fakes
“ 70% of the steel bars available in the market today are fake”, says Ms. Annamma James, a TMT steel dealer. “Crores of rupees have to be invested to install the high-tech infrastructure needed for the manufacture of TMT steel. Only big companies like METCON can afford to have such expensive manufacturing facilities”, she adds.
Many duplicate steel bars are being sold bearing the fake stamp of TMT. For a customer, it is not that easy to determine the quality of steel bars. Facilities for testing quality are also not easily accessible. Hence, it is advisable to go for the most reputed brands. Trusted engineers and architects have endorsed the same fact.
“When I was building my house, the architect had recommended Metcon of Metrolla Steels. The architect who had years of experience assured me that Metcon is a trusted brand in the market ” says Mr. Saji Varghese, a businessman in Cochin.
Quality TMT steel has optimum ductility
Original TMT steel bars are manufactured with advanced technological processes on modern rolling mills. They possess optimum ductility and can be bent as per the mason’s requirement. On the other hand, spurious quality steel bars would break on bending, because they are not made with advanced technologies. They may carry a TMT label but would not have any properties of an original TMT steel bar.
TMT steel bars of optimum ductility are even suitable when two steel bars have to be welded and joined together.
Ordinary steel bars are mostly manufactured from old ships, railway tracks, and so on. Hence they may contain impurities. These impurities reduce their quality and make them corrosive. Whereas, original TMT steel bars like METCON are not only less corrosive but do not easily wear out too. The unique rib pattern on their surface helps them to have a firm grip on the concrete. This in turn would help in the stability of the building. TMT steel bars also have the ability to withstand high temperatures up to 6000 C.
Ductile steel bars provide earthquake resistance
Concrete which is just made up of cement, sand, and water is likely to break when it is stretched or twisted even by a small degree. This is because it has very low tensile strength. But when steel bars of optimum ductility go into this concrete, they indirectly attain a tensile strength. “Buildings built with optimum ductility steel bars would be able to withstand mild tremors and earthquakes,” says Reji Zachariah a Structural Engineer. He also adds that such building may shake or tremble a bit, but would never collapse when earthquakes of small-medium scale strikes. Such buildings would have the necessary ‘flexibility’ and would easily recover to their former state. This is because they have ductile TMT steel in their structure. On the other hand, buildings built with ordinary steel bars can only be left to their fate.
Experienced architects say that some regions of Kerala are prone to seismic attacks. In such areas, a ‘framed’ construction style can be adopted. The concrete pillars, beams, and ceiling are first constructed and the walls are built in between the pillars. This would endow a flexible yet binding strength to the overall structure.
The Bureau of Indian Standards (BIS) has classified five seismic zones for the entire country as per their intensity. Kerala falls in Zone 3 and buildings constructed in this zone should ideally follow the recommendations of BIS.
Quality means more gains
Since TMT steel bars are built conforming to stringent quality parameters, they have a uniform structure and a fixed diameter throughout their length. The ratio between their length and weight would also be uniform everywhere. On the other hand, in low quality steel bars, this length-weight ratio would keep on varying.
Original TMT steel bars may be a little costlier than ordinary steel when considering their per kilogram cost. Still, when buying steel for construction purposes, it is more profitable to buy TMT Steel. Unlike original TMT steel, ordinary still bars do not have a consistent weight to length ratio. In a specific length of steel, ordinary steel may be heavier than original TMT steel. Remember, when buying steel we pay for it per kilogram. But when using, we lay it according to the length required. Hence, a buyer of ordinary steel would end up using up more steel. This fact is best illustrated through the comparative study given below:
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A comparative study
Steel required to build a 2000 sq. ft house: 3000 kg
Cost of TMT steel per ton: Rs. 28050
Cost of TMT for the above house: 28050 x 3 = Rs.1,26,225
Cost of ordinary steel for an above house: 26030 x 3 = Rs.1,17,135
The difference in cost: Rs. 9090
The fact of the matter: In place of 3000 kg of original TMT steel, 3500 kg of ordinary steel should be purchased to complete the house. That is half a ton of steel more. It would cost Rs.13,015 more.
Conclusion: Reputed TMT steel brands like Metcon are always manufactured in standard sizes and dimensions. Whereas, ordinary steel bars do not have a uniform structure and would cause heavy waste of steel. Hence, using TMT steel is more wise and profitable. Moreover, the buyer gets the reassurance of unique quality also.
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To sum up, in order to buy original quality TMT steel, a wise and pragmatic customer can either go for a reputed TMT steel brand like METCON or consult an engineer.
Quality testing facility
The Civil Engineering Department of colleges would have the facility for testing the quality of TMT steel. They would charge around Rs.350 for testing a sample.