Benefits of Torkari
Advantages of Using TORKARI
- The Quality Advantage
- The Cost Advantage
- The Size Advantage
The Quality Advantage
Superior Strength
fy = 550 N/sq.mm.
Ultimate = 585 N/sq.mm
Over 30% when compared to Tor 40 or Fe-415 where fy=415 N/sq.mm viz. 550/415 = 1.33 times.
The Quality Advantage
High Bond Properties
Torkari is Tri-Ribbed viz. Rib on three sides.
TMT and TOR-40 have ribs only on two sides.
Even 5mm TORKARI has ribs whereas 6mm MS is plain.
Bond strength is over 100%.
LESSER CRACK WIDTH DUE TO HIGH BOND.
Rolling Tolerance
Since the strength is more , it results in less area of reinforcement, thus reducing congestion of reinforcement.
As per IS code the acceptable rolling tolerance is 7%. In TORKARI due to its superior technology the rolling tolerance is restricted to 4%
Easily Weldable
100% Weldability
Being made from Low carbon mild steel with carbon less than 0.20%, it can be welded by metal arc welding process with normal electrodes.
CTD, TMT ( local rerollers)bars and 6mm MS are usually rerolled from scrap / ingots where the carbon content is not controlled. In fact the main reason for breakage during bending is due to rolling from scrap and high carbon content.
Other Quality Advantages
- Better fatigue strength.
- Advanced German Technology.
- Built in high creep resistance through adequate cold working.
- TRFI guidance and certification.
- Well equipped QC lab at factory. Clients witness of testing can be arranged before despatch. Can be used with any grade of Concrete
Satisfactory Bendability
TORKARI can be bent to form any type of hooks – U type or L type and also to form stirrups and ties by adopting suitable bend radius of over 25mm as per IS: 2052 – 1963.
Mandrel ( Pin dia) for TORKARI for Bending.
( 5 times the dia )
- 5mm TORKARI = 25 mm
- 7mm TORKARI = 35 mm
- 9mm TORKARI = 45 mm
(Atleast ensure the pin dia is 25mm at Site.)
THE SIZE ADVANTAGE
- Smaller diameters from 5mm onwards.
- Available in 5mm, 7mm and 9mm.
- 5mm TORKARI can be used in place of 6mm MS.
- 7mm TORKARI can be used in place of 8mm Tor-40.
- 9mm TORKARI can be used in place of 10mm Tor-40.
As minimum reinforcement
- In slabs only 8mm Fe-415 is used in most cases as it is the minimum dia available.
- As per IS the max. spacing is 3d for main reinforcement and 5d for distribution steel / temperature reinforcement.
( d – eff. Depth) - Due to site conditions and slab thickness the max. spacing of 8mm in slabs is restricted to 250mm.
- The minimum reinforcement as per code is 0.12% Ast whereas the above works out to 0.17% Ast.
5mm in place of 8mm Tor-40.
Due to the poor quality of 6mm MS which is rerolled from scrap most of the consultants recommend 8mm Tor-40.
In those areas where 6mm MS would suffice but 8mm Tor-40 is used we can implement 5mm Torkari. In a 110mm slab the spacing of 8mm is limited to 250mm since the max. spacing as per IS is 3d.
BENEFITS OF HIGH STRENGTH TOR-KARI (TOR 55 GRADE) STEEL REINFORCEMENT BARS
Savings due Higher Strength
TOR-KARI steel has high 0.2% proof strength of 550 N/sq.mm resulting in large saving upto 30% over the 40 grade steel with a proof strength of 415 N/sq.mm
Savings due to Smaller Dia
High Strength – TOR-KARI steel reinforcement bars (TOR 55 Grade) are made by a process of cold rolling from mild steel coils and consequently come out in small diameters from 4.5 mm to 9 mm. This range of sizes will not only cause structurally superior components in addition to savings in steel consumption, in comparison to the 40 Grade bars which come in a minimum dia of 8 mm. Conventional high strength deformed bars of Fe 415 grade of dia 8 mm and 10 mm can be conveniently replaced by High Strength TOR-KARI reinforcement bars (TOR 55 Grade) of dia 7mm and 9mm. TOR-KARI of dia 5mm can also economically replace mild steel bars of dia 6/6.8 mm often used as secondary reinforcement.
Better Structural Performance
Due to the smaller diameters and High Strength, TOR-KARI (TOR 55 Grade) steel reinforcement gets more closely placed and thus leads to smaller and more evenly distributed bending as well as shrinkage cracks in structural components.
Precast Components
Due to the smaller diameters available, there is unlimited possibility for use of High Strength TOR-KARI (TOR 55 Grade) steel reinforcement bars in precast components.
Economy
Since TOR-KARI is available in smaller diameters and has far superior strength and bond properties compared to even Fe 415 grade steel (Tor 40 for example), it can be efficiently and effectively used to achieve maximum economy.
The cost savings are 8 to 10% when TOR-KARI is used in place of Fe415 grade steel and as much as 35% when used in place of plain M. S.
