To Know About Building Steel Bars
In this blog, we are talk about the steel bar and type of bar used for constructing a house, to know more about layout of house-plot, laws & norms, restoration, civil price and finishing value.
Mild steel bars (as per IS: 432, part-I -1982)
The strength, versatility, and affordability of carbon metal bar make it one of the maximums broadly used manufacturing and construction materials withinside the world. Given the range of various sizes and shapes of metal bar that manufactured, steel bar products provide superior structure and help for a huge variety of construction, architecture, and heavy commercial programs throughout the world.
Mild metal bars are used for tensile strain of RCC (Reinforced cement concrete) slab beams etc. in reinforced cement concrete work. These steel bars are simple in ground and are round sections of diameter from 6 to 50 mm. These rods are synthetic in long lengths and can be reduce and be bent effortlessly without damage.
Deformed steel bars (as per IS: 1786-1985)
As deformed bars are rods of steels provided with lugs, ribs, or deformation at the floor of bar, those bars reduce slippage in concrete and will increase the bond among the 2 materials. Deformed bars have additional tensile stresses compared to moderate smooth metal bars. These bars can be used without end hooks. The strain should be spaced along the bar at substantially uniform distances.
To limit cracks that can develop in strengthened concrete round moderate steel bars because of stretching of bars and a few losses of bond under load it is common to use deformed bars which have projecting ribs or are twisted to enhance the bond with concrete. These bars are produced in sections from 6mm to 50mm in diameter.
In addition, the strength of bonds of deformed bars calculated need to be forty to 80% better than that of plain round bars of equal nominal size. And it has extra tensile strain than that of plain round bars of equal nominal size.
Cold twisted deformed bars are recommended as fine quality metal bars for construction work through structural Engineer.
Various Grades of Mild Steel Bars
Reinforcement bars in accordance with standard IS No. 432 part-I can be classified into following types.
1) Mild Steel Bars: Mild steel bars can be supplied in two grades
a) Mild steel bars grade-I designated as Fe 410-S or Grade 60
b) Mild steel bars grade-II designated as Fe-410-o or Grade 40
2) Medium Tensile Steel Bars designated as Fe- 540-w-ht or Grade 75
Physical Requirement:
S.No |
Types of nominal size of bars |
Ultimate Tensile Stress N/mm2 minimum |
Yield Stress N/mm2 |
Elongation Percent minimum |
1. |
Mild Steel Grade I or Grade 60 |
|
|
|
|
For bars up to 20mm |
410 |
250 |
23 |
|
For bars above 20mm upto 50 mm |
410 |
240 |
23 |
2. |
Mild Steel Grade-II or Grade 40 |
|
|
|
|
For bar up to 20mm |
370 |
225 |
23 |
|
For bars above 20mm upto 50 mm |
370 |
215 |
23 |
3. |
Medium Tensile Steel Grade-75 |
|
|
|
|
for bars up to 16mm |
540 |
350 |
20 |
|
for bars above 16 mm up to 32 mm |
540 |
340 |
20 |
|
for bars above 32 mm up to 50 mm |
510 |
330 |
20 |
Grade II Mild steel bar are not recommended for use in structures located in earthquake zones subject to severe damage and for structures subject to dynamic loading (other than wind loading) such as railways and highways bridges.
Each batch or delivery of metal bars on the ground brought into the workplace must be tested in the laboratory before use in the framework of the work. However, for small work you may use mild metal bars based on verifying tests outcomes made through manufacturer in his own laboratory, which can be available with supplier.
Some manufacturers have stamped the grade of MS bars with their mark / appeal and provide grade testing and certification. Based on the above information, it is possible to gradually maintain soft metal bars on the construction site.
Steel Bars for RCC Work
All completed steel bars for reinforced work must be smartly rolled to the measurement and weights as specified. They should be sound, free from cracks, surface flaws, laminations, rough, jagged, and imperfect edges, and different defects. It needs to be completed in a work manlike manner.
General precautions for steel bars in reinforcement
-
Steel bars are clear, free from loose mil scales, dust and loose rust coats of paints, oil or other coatings which may destroy or reduce bond strength.
-
Steel bars should be stored in such a way as to avoid distortion and to prevent deterioration and corrosion.
-
Steel bars should not be clean by oily substance to remove the rust.
-
The bar is bent correctly and accurately to the size and shape as shown in drawings.
-
If possible, the bar of full length is used.
-
Overlapping bars do not touch each other and these should be kept apart with concrete.
-
The overlap if given should be staggered.
-
The cranks in the bar at the end should be kept in position by using spots.
-
The steel bars should not be disturbed while lying cements concrete.
-
Required cover under steel bars should be given before laying the cement concrete.
-
No overlap is given in the bar having a diameter more than 36 mm, if required, the bar should be welded.
Weight of Different Steel Bars
When we need to buy mild steel components from the market, the trader evaluates the steel member load by weight.
When any kind of steel members to be used in residence construction is required, we calculate the length of metallic member in ft or meter, however we're ignorant approximately the weight of metallic.
Here is information of weight per meter for numerous types of steel members: -
This will help us for estimated weight and cost. It will also help when buying to avoid weight theft.
M S Steel round & square Bar |
|||
Sr.No. |
Diameter of steel bar |
Weight per meter |
|
|
Round Bar |
Square Bar |
|
a |
6 mm |
0.22 Kg. |
0.28 Kg |
b |
8 mm |
0.39 Kg |
0.50 Kg |
c |
10 mm |
0.62 Kg |
0.78 Kg |
d |
12 mm |
0.89 Kg |
1.13 Kg |
e |
16 mm |
1.58 Kg |
2.01 Kg |
f |
20 mm |
2.46 Kg |
3.14 Kg |
g |
25 mm |
3.85 Kg |
4.91 Kg |
h |
28 mm |
4.83 Kg |
6.15 Kg |
i |
32 mm |
6.31 Kg |
8.04 Kg |
j |
36 mm |
7.99 Kg |
10.17 Kg |
k |
40 mm |
9.86 Kg |
12.56 Kg |
l |
45 mm |
12.49 Kg |
15.90 Kg |
m |
50 mm |
15.41 Kg |
19.62 Kg |