TMT Bars - Thermo-Mechanical Treated Bars

WHAT IS TMT BAR - THERMO-MECHANICAL TREATED BARS?

Thermo-Mechanically Treated Bars, (TMT Bars), are Extra High Strength Reinforcing bars which replacing any form of cold twisting, the technology of yesteryears. In this process, the steel tmt bars receive a short, intensive cooling as they pass through the specially resigned Tempcore Water Cooling System after the last Rolling Mill Stand. The sudden quenching converts the surface layer of the steel bar to a hardened structure.

This phase of intensive cooling by the Tempcore System is followed by further cooling in atmosphere, so that the temperature between the core (which is steel hot) and the cooled surface layer is equalized, and the surface layer gets tempered by the heat from the core. The resulting structure is a tempered martensite zone at the periphery and a fine grain ferrite pearlite structure in the central zone.

 

PRODUCT RANGE

TMT BARS / De- formed Bars (Grade Fe-415/ 500/ 550 & Fe-415D, Fe500D, Fe 550D, Fe 600): 8 mm - 50 mm dia. 

AZAR BARS - Zinga Coated TMT BARS / De- formed Bars (Grade Fe-415/ 500/ 550 & Fe-415D, Fe500D, Fe 550D, Fe 600): 8 mm - 50 mm dia.

TMT / De- formed Bars Corrosion Resistance Bars (Grade Fe-415/ 500/ 550 & Fe-415D, Fe500D, Fe 550D, Fe 600): 8 mm - 50 mm dia.

 

INTERNATIONAL QUALITY STANDARDS

Manufactured conforming to various international standards, viz. IS:1786 Grade Fe415/ Fe500/ Fe550 / Fe 600 / Fe 415D/Fe 500 D/ Fe 550 D / Fe 500 S of BIS of India, ASTM A615 Grade 60 of the USA, BST 500 of DIN 488 of Germany, BS 444 Grade 460 of Great Britain,among others.

 

INTERNATIONAL CUSTOMERS

SRMB TMT Bars are successfully exported to SAARC countries, viz. Nepal, Bangladesh and Bhutan.

 

FEATURES

Strength

SRMB TMT Bars are available in Fe: 415 /500 /550/ 600 & Fe-415D, Fe500D, Fe 550D, Fe 600 grade which are much stronger than yesteryears' conventional Bars and give upto 20% stronger concrete structure with same quantity of steel.

Elongation

More strength with higher elongation is one of the unique features of SRMB TMT Bars. It makes a concrete structure not only sound but safe also from earthquake related natural calamities.

Bend Properties

Due to unique feature of greater elasticity in SRMB TMT Bars, it provides a very good bending/ re-bending option during application in construction.

Corrosion Resistant

SRMB TMT Bars provides very good corrosion resistance due to it’s controlled chemistry of raw material inputs, which provides a longer life concrete structure.

Fatigue Resistant

The unique feature of SRMB TMT Bar is its high Fatigue Resistance on dynamic loading on account of the high strength of the surface layer.

Weld-ability

SRMB TMT Bars with low carbon equivalent content can be used for butt/ lap and other weld joints without reduction in strength at the weld joints.

Technology

SRMB TMT Bars are backed by latest on Tempcore Technology, which makes it highly superior product in construction industry. To know more about WINGRIP Technology.

 

WHAT IS THE APPLICATION OF TMT BARS?

These bars can be used for general concrete reinforcement in building, bridges and various other concrete structure. They are highly recommended for use in high- rise building because of the saving of steel through higher strength. TMT Bar, the new generation high strength ribbed reinforcement bar, is a product from SRMB  Srijan Private Ltd. It is different from traditional bars in its method of manufacture and consequently, in its combination of properties.

SECTION META CHART

The standard section weight and difference with 'SRMB Srijan Private Ltd TMT' is enumerated by the table below:

Benefits of Using SRMB's Srijan Pvt Ltd TMT Bars

N.B.: These are indicative results of general standard lots of "SRMB TMT ". There may be variance as per customer requirement/standards applicable.

 

WHAT ARE THE TYPES OF TMT BAR WE MANUFACTURE?

Normal TMT section

Fe 415 grade :Fe 415 grade was the first innovation in TMT series which replaced conventional CTD bars with much better yield strength ductility and elongation .The journey of modern days construction steel started with the introduction of Fe-415 grade TMT bars .

 

WHAT ARE THE ADVANTAGES OF USING TMT BARS MANUFACTURED BY SRMB STEEL?

Features of Fe 415 grade TMT Bars are as follows:

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
415.0	485.0	14.5	0.30	0.060	0.060	0.110

Fe-415 D: The D variety of TMT bars were introduced by BIS in their latest armament in the year 2008. This category of TMT Bars demonstrate higher tensile strength and ductility on and above normal grade TMT bars. D variety TMT bars are manufactured through special category of billets and critically controlled thermal treatment during manufacturing process. The best part of D variety TMT bars are these are the ideal product for earthquake resistance and totally free of mechanical fatigue .

Features of Fe 415D grade TMT Bars are as follows:

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
415.0	500	18	0.25	0.045	0.045	0.085

Fe 500 Grade : Fe 500 grade TMT Bars were introduced as an one step up technological marvel over conventional fe 415 grade product . The superior tensile strength in Fe 500 TMT bars resulted in approximately 17% lesser consumption in steel in construction .

Features of Fe 500 grade TMT Bars are as follows:

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
500.0	545.0	12.0	0.30	0.055	0.055	0.105

Fe-500 D: The D variety of TMT bars were introduced by BIS in their latest armament in the year 2008. This category of TMT Bars demonstrate higher tensile strength and ductility on and above normal grade TMT bars.D variety TMT bars are manufactured through special category of billets and critically controlled thermal treatment during manufacturing process. The best part of D variety TMT bars are these are the ideal product for earthquake resistance and totally free of mechanical fatigue .

 

WHAT IS WINGRIP TECHNOLOGY?

1st to introduce India's innovative, patented designed ribs that has been named Wingrip Technology. It makes the home so secure by creating strong bonding with the concrete, so that no threat can ever bowl it out. For more information please click here.

WHY TMT BARS ARE ESSENTIAL FOR CONSTRUCTING BUILDINGS?

The strength of a building lies in its foundation. And good quality TMT bars are essential construction material that makes the concrete structure strong, securing it from any damage.  

TMT bars have an excellent tensile strength and are mainly used to reinforce concrete. It’s because TMT bars are designed in such a way that they form and excellent bonding with the concrete. For this reason, TMT bars are widely preferred for all the key construction activities around the country and the world.

 

HERE ARE A FEW REASONS WHY TMT BARS ARE A MAJOR FACTOR IN CONSTRUCTION:
 

• TMT bar are good during earthquake where it helps to withstand the shear force and TMT bars have good expansion capacity. It holds the coloumns against failure during earthquake.
• TMT bars have superior strength.  These bars come in a variety of grades and are much stronger than conventional bars. Compared to steel, TMT bars give extra strength to the concrete structure. This feature makes them a cost-effective option for construction.
• TMT bars have unique bending ability. And that’s why it is ideal for any construction work. It can be given any shape to meet the architectural and design needs of the building.
• TMT bars are resistant to corrosion. This is an important feature as its anti-corrosive properties ensure a longer life for the concrete structure.
• These bars are resistant to fatigue. This is yet another unique and important feature of TMT bars. These bars can withstand any dynamic loading due to their excellent strength of the surface layer. This makes TMT bars an essential choice for super strong buildings.
• TMT bars are resistant to earthquake. They have a soft ferrite-pearlite core and a high strength outer layer. This makes them strong enough to withstand any seismic activity, thus increasing the longevity and strength of the concrete structure.
• TMT bars can withstand high temperature and are pretty flexible to work with. That’s another reason why it’s better to use TMT bars than other conventional bars.

Keeping this in mind, SRMB Srijan Pvt Ltd launched their Earthquake resistant TMT bars—SRMB 500+SR., it would ensure the “survival of the fittest” building if earthquake strikes

Features of Fe 500 D grade TMT Bars are as follows:

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
500.0	565.0	16.0	0.25	0.040	0.040	0.075

Fe 550 Grade & Fe 600 Grade: Fe 550 grade & Fe 600 grade TMT Bars were introduced to further increase the technical excellence of TMT bars and propensity of consumption of steel in construction projects drastically got reduced due to much higher tensile strength and load bearing capabilities of these technologically superior grade of TMT bars .Gradually the structural engineer fraternity is inclining towards these high end TMT Bars.

Features of Fe 550 & Fe 600 grade TMT Bars are as follows:

Grade Fe- 550

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
550.0	585.0	10.0	0.30	0.055	0.050	0.100

Grade Fe- 550 D

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
550.0	600.0	14.5	0.25	0.040	0.040	0.075

Grade Fe- 600

MECHANICAL PROPERTIES			CHEMICAL PROPERTIES
0.2% Proof Stress / YS (N/mm²) Max.	Tensile Strength (N/mm2)Min	Elongation %	C (%)	S (%)	P (%)	S & P (%)
600.0	660.0	10.0	0.30	0.040	0.040	0.075

Reinforcement bars of wire rods are used in conjunction with cement concrete to build up a reinforced concrete structure which has a much higher strength. However, corrosion of reinforcement bars arises due to the presence of chloride ions in the concrete, and cement which contains calcium hydroxide produces calcium carbonate in the presence of carbon dioxide and moisture in the environment. The formation of calcium carbonate lowers the pH value of Steel thus making it more prone to corrosion. The corroded products are detrimental because they are more voluminous and exert pressure in the concrete leading to cracking. To protect steel from corrosion CRS TMT was introduced to prolong the longevity of RCC structure.

CRS TMT bars are produced with utmost care and with adequate addition of corrosion resistance elements such as Copper, Chromium and Phosphorous. All process controlled parameters are adhered to strictly at Steel Melting Shop and at rolling mill. The international quenching technology of repute (TEMPCORE CRM- Belgium) compliments the entire process to ensure the desired properties in CRS TMT Bars.

 

WHAT ARE THE AREAS OF USE OF CRS TMT?

• Highly humid and moist areas
• Marine atmosphere
• Bridges, dams, roofing prone to seepage of water
• Back water areas

 

SRMB CRS TMT BAR

SRMB CRS TMT Bar is produced by adding alloying elements like Cr, Cu, Ni, Mo and P, either individually or in combination, to improve allied product properties. In the Electric Furnace, corrosion resistant elements like phosphorus, copper/chromium are added to the molten steel, while carbon and sulphur is reduced further through refining and deslagging. The microalloyed molten steel is then casted into billets and rolled in a controlled quenching and tempering process to impart the desired corrosion-resistant properties to the end product.

 

ADVANTAGES OF SRMB CRS BAR

• Longer life due to superior corrosion resistant
• High yield strength coupled with superior ductility and bendability
• No additional precaution required in material handling and transportation
• No extra operations required during fabrication
• Easy to weld
• Can be sent and re-bentusing very small mandrel

Deterioration of reinforced concrete by corrosion of the carbon steel reinforcing bars (Rebars) is a worldwide problem. The corrosion product (rust) occupies a greater volume than the original steel bar and this creates a pressure which causes cracking and subsequent bleeding of the surrounding concrete.

Corrosion of carbon steel rebars is greatly accelerated when chlorides are present in the concrete (coupled with requisite moisture and oxygen levels to sustain the corrosion reactions). This situation gets aggravated in constructions at the coastal areas due to inherent extra salinity in its surroundings.

However, there is increasing interest in the use of reinforcing materials that have inherently good corrosion resistance, thus minimizing the need for maintenance and monitoring of the structure. Faced with the problems of costly repair / replacement of important structures, the governing authorities are increasingly demanding a greater emphasis on Life Cycle Costs for new construction projects, as opposed to considering only the initial capital costs.

Billets manufactured from steel containing desired quantities of Copper and Chromium / Copper and Phosphorus having inherent corrosion-resistant properties are being used for hot-rolling of CRS TMT rebars. The bars then undergo controlled quenching and tempering to impart the desired corrosion-resistant properties to the end product.

 

CHEMICAL COMPOSITION OF SRMB CRS BAR

CHEMICAL COMPOSITION OF CRS MATERIAL (Cu / P Grade)
ELEMENTS	COMPOSITION
% C	0.15 (MAX.)
% Mn	0.50 (MIN.)
% Cu	0.30 (MIN.)
% P	0.120 (MAX.)
% Cr	Not required
Remarks	Ref. : IS:1786/2008, Clause no. 4.2, note 3

 

CHEMICAL COMPOSITION OF CRS MATERIAL (Cu / Cr Grade)
ELEMENTS	COMPOSITION
% C	0.15 (MAX.)
% Mn	0.50 (MIN.)
% Cu+ % Cr	0.40 (MIN.)
% P	0.120 (MAX.)
Remarks	Ref. : IS:1786/2008, Clause no. 4.2, note 3

 

PHYSICAL PROPERTIES OF SRMB CRS BAR

Grade	Fe-415	Fe-415 D	Fe-500	Fe-500 D	Fe-550	Fe-550 D	Fe-600
Yield Strength (N/mm2) Min	415	415	500	500	550	550	600
Tensile Strength, (N/mm2) Min	10% more than actual 0.2 percent proof stress/Yield Stress but not less than 485 N/mm2	12 % more than actual 0.2 percent proof stress/Yield Stress but not less than 500 N/mm2	8 % more than actual 0.2 percent proof stress/Yield Stress but not less than 545 N/mm2	10% more than actual 0.2 percent proof stress/Yield Stress but not less than 565 N/mm2	6% more than actual 0.2 percent proof stress/Yield Stress but not less than 585 N/mm2	8% more than actual 0.2 percent proof stress/Yield Stress but not less than 600 N/mm2	6% more than actual 0.2 percent proof stress/Yield Stress but not less than 660 N/mm2
Elongation (%) Min	14.5	18.0	12.0	16.0	10.0	14.5	10.0