High strength and ductility make TMT bars a quintessential part of today’s construction industry in India. However, as a beginner in the construction world, you may need help understanding the complexities associated with selecting a durable and strong TMT bar. For this reason, this post has come up with the most commonly asked questions contractors ask before buying the best TMT bars at wholesale rates from reliable manufacturers and suppliers.
Top Frequently Asked Questions about TMT Bars Before Buying
If you are in the market to buy TMT bars in bulk, the following are the frequently asked questions commonly asked by construction professionals before making the purchase:
Question 1 – What Are TMT Bars?
In short, thermo-mechanically treated bars are the high-strength reinforcement bars. They have become crucial materials in the construction projects. The bars also ensure the following based on the grades used:
- Higher strength to ensure structural integrity
- Ductility to prevent external damage during earthquakes and other natural calamities
- Corrosion resistance that improves its durability
Made from steel, they undergo a special treatment for which they are tough on the exterior and soft on the inside. So, the strong outer layer makes these bars easily bendable and pull forces. Thus, it’s best suited for seismic regions.
On the other hand, the soft inner core ensures better ductility. So, when the bars are bent, they don’t break. The flexible and strong bars are suitable for construction projects like slabs and beams, dams, bridges, and more.
Question 2 – What Do You Mean By Thermo-Mechanically Treated Bars?
TMT bars undergo a unique type of treatment – thermo-mechanical treatment. Here, raw materials like coal, iron ore, etc. are used. The iron ore is melted and converted into molten iron. Then, this molten iron is refined to eliminate impurities.
After this, the billets are heated to get the desired shape and size. Then comes quenching, where the outer layer of the bar is cooled to create a strong and rigid martensitic structure. In the self-tempering method, the heat is transferred from the inner to the outer layer. Then, the bars are cooled naturally.
Question 3 – Why TMT Bars Are Used?
Considering the following reasons, TMT bars are used in the construction projects:
- The soft inner core offers flexibility
- Excellent tensile strength, so they can withstand heavy loads
- Superior bond with concrete that improves the strength of the structure
- Improved resistance to corrosion
TMT bars are used as a durable construction material for the benefits mentioned above.
Question 4 – What Size of TMT Bars Shall You Purchase?
When it comes to the TMT bar sizes, they are available in a wide range of sizes:
6mm to 12mm –
They are used for residential buildings and small constructions, such as columns, beams, and slabs. A 6-12 mm TMT bar ensures an outstanding balance of flexibility and strength.
25mm and above –
They are used for large-scale projects that require significant load-bearing capacity, such as dams, bridges, foundations, and high-rise buildings.
Question 5 – What Are the TMT Bar Grades Available?
You can find a wide range of TMT bar grades available in the market:
- Fe-415
It has a minimum yield strength and is used in small-scale constructions, residential buildings, etc.
- Fe-500
This particular grade has a minimum yield strength. It’s used in building columns and slabs. It ensures strength and flexibility. This is why it is a popular choice for construction.
- Fe-550
Fe-500 is most suitable for projects requiring higher strength, like dams, bridges, high-rise buildings, etc.
- Fe-600
This grade has the highest strength and is more commonly used in heavy-duty construction projects, such as large-scale infrastructure and industrial structures.
Other options available in the market are Fe-500D and Fe-550D. The D in the bars indicates ductility, which is why they are more common in construction in seismic regions prone to natural disasters like earthquakes.
Question 6 – How to Measure TMT Bar Strength?
It is true that while BIS and ISI certifications of TMT bars ensure strength, there are specific ways to understand the durability of TMT bars. First comes the tensile strength testing process, where you can measure its durability using the UTM or Universal Testing Machine. This test is conducted by the manufacturers.
Then comes the bending and rebending test. Here, the section of the bar is bent at 180 degrees. A quality TMT bar doesn’t crack or break before rebending. The rebend test involves the bar to bend at 135 degrees. The TMT bar is kept in boiling water at 100 degrees for half an hour. This allows it to cool down. After this, it is twisted again.
You can conduct a visual inspection before buying the bars from the manufacturer or supplier. Here, you need to check the sharpness and consistency of the bar by checking the structure. Ensure the bar is free from unevenness, rust, and cracks. Notably, these methods offer an understanding of the bar’s quality.
Question 7 – What’s the lifespan of TMT Bars?
The lifespan of TMT bars depends on a few parameters, as mentioned below:
- TMT Bar’s Quality
Premium-quality TMT bars (with strong manufacturing processes and excellent raw materials) ensure longevity. As a result, these bars last longer and ensure the structure’s structural integrity.
- Maintenance and Other Details
Routine maintenance and inspections of buildings and structures help detect internal issues and address potential issues before they become more significant.
- External Aspects to Consider
When the TMT bars are exposed to moisture and high temperatures, corrosion may build up, reducing their lifespan.
Altogether, the lifespan of TMT bars may range between 50 and 70 years, based on the above factors.
Wrapping up
Understanding the above things about TMT bars will help you choose the right products for your next construction project. Now that you understand the most commonly asked questions about TMT bars, it’s time to consult the top rated TMT steel bar manufacturers. Always remember to choose the right size and grade of the bars from a reliable supplier.
Leave a Reply