Thermo-Mechanically Treated (TMT) Bar

Thermo Mechanically Treated Bar is high-strength reinforcement steel having a tough outer core and a soft inner core. TMT Steel rebar is currently the most used steel reinforcement bar in the construction field. They are known for their high tensile strength and ductility. There are different grades for TMT rebar’s namely Fe 415, Fe 500, Fe 550, and Fe 600.

Origin of TMT Bar

Thermo Mechanically Treated (TMT) was first introduced in 1979 as conformed to IS 1785:1979. Since its introduction, there has been a huge demand for these reinforced steels.

Need for Thermo Mechanically Treated (TMT) Bar:

TMT Bars are used as reinforcement in the concrete.

Concrete shows good compressive strength but poor tensile strength which demands reinforcement.

Desired properties of reinforcement are:

• High Strength.
• High tensile strain.
• Good bond to the concrete
• Thermal compatibility
• Durability in the concrete environment.

Advantages of Thermo Mechanically Treated (TMT) Bar:

• TMT Bar is environment-friendly as it can be recycled and reused without any loss of quality.
• TMT Bar is incredibly flexible, TMT Bar can be created into required steel frames.
• TMT Bar can withstand fires and earthquakes.
• TMT Bar is easy to transport due to its lightweight build.
• TMT Bar can increase the pace of the construction process.
• TMT Bar, with their superior malleability, ductility, strength, and better weldability.

Comparison between TMT Bar and HYSD Bar:

•  TMT Bar does not surface flaws when compared with HYSD bars as unlike HYSD bars, as the manufacturing process in the TMT Bar does not involve twisting or torsional stress.
• When compared with TMT Bar, the HYSD bar increase the consumption of steel by 8% to 11% when used in the same construction.
• TMT Bars come with a stronger external layer, something which is missing in HYSD due to the ductile nature of the core and hard crystalline surface of TMT steel.
• When compared with TMT Bars, HYSD bars cannot provide flexibility and ductility, thus limiting their use in different types of construction works.
• TMT Bars have less residual stress due to the better manufacturing process and have better tensile strength when compared with the HYSD bar.
• TMT Bar is effective in the earthquake-prone zone and copes better with sudden load surges and absorption when compared with the HYSD bar.
• TMT Bar is more corrosion resistant when compared with HYSD bars, this is mainly due to rapid quenching and tempering used in TMT bar manufacturing process.

Source: Mithun Debnath (megaturbotmt)