Check Out the Difference Between TMT Bar And TOR Steel Bar
For decades, steel has been an integral part for all types of constructions. It reinforces the concrete and protects the construction structure from getting worn-out from rust or any natural calamity.
There are different types of steel bars. Generally, the type of steel bars varies depending upon factors like geography and environment. Till the 1990s, TOR steel was used vastly. Later, TMT bars superior ductility and other qualities gradually wiped-out TOR steel from the market.
Tor Steel & TMT Bar
TOR is the brand name for ‘Toristeg Steel Corporation’ of Luxembourg. For a brief period, TOR steel, was one of the best grades of steel used in concrete reinforcements. Produced from mild steel billets with limited carbon content, TOR steel is more tensile stress, and its high elasticity value comes from the surface deformation created by twisting of the steel after elongation. As a result, this created residual stress, making TOR steel corrosion prone.
TMT (stands for Thermo-Mechanically Treated) Bar. It is described as a high-strength reinforcement bar with a tough outer core and soft inner core. Since its inception, TMT bars have proven to be extremely viable for reinforcing concrete structures. And it is known for its high-strength, sturdy build and robust appearance. Also, they are corrosion resistance due to its chemical properties, as per ISO Code. Today, TMT bars are commonly used as tensioning device to reinforce concrete and helping it resist compressive forces.
TMT (Thermo-Mechanically Treated) Steel Bars are ideal for building earthquake-resistant structures. They not only help to minimize the effects of damages during any seismic activities, but they also offer the perfect optimum balance between toughness and flexibility (Elongation).
Differences Between TMT Bar & Tor Steel
The processes through which both TMT bars and TOR steel are manufactured are different. And both have unique features. However, the TMT bars have clear advantage over TOR steel. According to IS 1786, TMT is better than TOR steel. And the below mentioned features are reasons as to why TOR steel is less preferred. And not considered as best steel bars.
Tensile Strength:
TMT bars have higher value of yield-strength when compared to TOR steel as it has 2 layers of soft inner core and hard outer core that can withstand the external force and stress. Usage of best TMT bars will result in lower steel quantity. But the use of TOR steel results in 20% more steel quantity.
Ductility:
Ductility refers to the ability of any material to deform, without collapsing even after reaching the failure load. TMT bars possess superior ductility when compared to TOR steel. And possess extraordinary strength which allows them to help a building structure acquire 20% extra strength.
Elongation:
Elongation refers to the ability of any material to elongate before failure. The higher the elongation, the higher will be the ductility. When compared to TOR Steel, TMT bars have hard outer layer and soft inner-core. And this makes construction structures strong and flexible. It will be well-insured from the dangers of natural calamities.
Bendability:
Though both TMT bars and TOR steel possess a good track-record of bendability, TMT steel’s unique soft inner and hard outer core structure effectively eliminates the possibility of breakage during the re-bend process allowing greater elasticity which allows them to bend more to achieve various shapes. Although TOR steel exhibits good bendability, it is susceptible to re-bend breakage.
Weldability:
TMT bars with low carbon content are highly weldable when compared to TOR steel. The low-carbon ingredient in TMT bars makes them a viable choice for hassle-free welding works. Thus, construction designers and architects can create innovative structures without compromising.
Durability:
The residual strain in TOR steel initiates faster corrosion process than in TMT bars. Thanks to their manufacturing process and processing of raw materials. TMT bars stay highly resistant to corrosion. During any construction works, the TMT bars can stay exposed to water for a longer period without getting affected.
Seismic-Resistant:
TMT bars are intrinsically hard and strong than TOR steel. TOR steel softens in the long run and makes them vulnerable. On the other hand, TMT bars with their excellent concrete bond of soft ferrite-pearlite core and reinforcement strength, allows them to absorb a greater amount of energy released during a natural calamity and ensure the longevity of building structures.
Rust Resistant:
TOR steel corrodes due to its high concentration of chloride ions. On the other hand, TMT bars due to absence of Chloride ions and are very highly rust and corrosion-resistant which makes them ideally suitable for construction structures in humid and coastal areas.
Fire-Resistant:
TOR steel contains low thermal stability. On the other hand, TMT bars with their higher thermal stability can retain more than 80% of the ambient temperature yield strength at 300°. This helps the construction structures to stay safe and secure during fire disasters.
Flexibility:
When compared to TOR steel, TMT bars are extremely flexible which allows them to endure high temperature and humidity levels. In addition, they do not crack or break even after turning and bending 180 degrees.
Bonding:
TMT bars bond better than TOR steel with cement. This is possible due to the superior bonding strength of the ribs on the surface of the TMT bars that run across the entire length. Combined with superior strength, TMT bars’ strong bonding capabilities allow them to form a strong structure with concrete or cement. And this provides superior strength to the construction structures and increasing their longevity.
TMT Bars Are Easy On The Pocket
TMT bars are also more affordable when compared to TOR steel. That is because they do not go through additional hardening processes like TOR steel. Constructions consume fewer TMT steels than TOR steels, as it contains 15% less carbon, sulphur, and phosphorus. This reduces energy as well as money spent on deformation processes. Moreover, TMT bars also use 8-11% steel compared to TOR steel and gives longer life to construction structures.
TMT Bars Are Ideal for Indian Climate
India with its hot and humid weather for most part of the year, TMT bars remain the best bet. TMT bars thermos-mechanical treatment technology prevents rust and corrosion. Whereas TOR steel bars contain chloride irons which makes them highly vulnerable in humid conditions.
Though both TOR and TMT bars exhibit high strength, TMT bars are significantly more superior and better suited for large concrete construction structures due to its strength and capacity to survive any weather condition and durability especially in coastal areas where humidity remains a major issue. Their superior ductile feature also helps to protect construction structures during an earthquake.
If you’re looking to purchase TMT bars, it’s important to understand that the true sense of TMT bars lies in the proper balance between toughness and flexibility. So, choosing the right TMT bar will help to begin a new construction on the right note.
Grades Of TMT Bar
There are several grades of TMT bars in the marketplace. The higher the grade, the better the TMT bars are. Herein, Fe 550D Grade TMT Bars offer the perfect balance of strength and flexibility according to IS Standards. Hence, it is recommended for all types of construction purposes.