Things Site Engineers Must Know About Reinforcement and Steel Bars
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As Per Indian Guidelines Only.
Clear cover to main reinforcement in
Footings : 50 mm
Raft foundation Top : 50 mm
Raft foundation Bottom/ sides : 75 mm
Strap Beam : 50 mm
Grade Slab : 20 mm
Column : 40 mm (d>12mm) 25 mm (d= 12mm)
Shear Wall : 25 mm
Beams : 25 mm
Slabs : 15 mm or not less than diameter of the bar.
Flat Slab : 20 mm
Staircase : 15 mm
Retaining Wall on Earth : 20/ 25 mm
Water retaining structures : 20 / 30 mm
Sunshade (Chajja) : 25 mm
Hook for stirrups is 9D for one side
No. of stirrups = (clear span/Spanning) + 1
For Cantilever anchorage length for main steel is 69D
“L” for column main rod in footing is minimum of 300mm
Chairs of minimum 12 mm diameter bars should be used.
Minimum diameter of dowel bars should be 12 mm
Lap slices should not be used for bar larger than 36 mm.
In steel reinforcement binding wire required is 8 kg per MT.
Lapping is not allowed for the bars having diameters more than 36 mm.
Minimum number of bars for a square column are 4 and for circular column are 6.
Longitudinal reinforcement should not be less than 0.8% and more than 6% of gross C/S.
Weight of rod per meter length = d2/162 where d is the diameter in mm
All reinforcement shall be free from mill scales, loose rust & coats of paints, oil or any other substances.
Main bars in the slabs shall not be less than 8 mm (HYSD) or 10 mm (Plain bars) and the distributors not less than 8 mm and not more than 1/8 of slab thickness.
In case of spacing of bars
Provide the diameter of the bar, if the diameter of the bar are equal.
Provide the diameter of the larger bar, if the diameter are unequal.
5mm more than the nominal maximum size of the coarse aggregate.
Things Site Engineers Must Know
Check out the Unit Weights and Conversion which will be required on construction site here
We at engineeringcivil.com are thankful to Er Vikrant for submitting this construction site check list which is of great use to all civil engineers.
Dear Sir, Please Explain and Calculated Circular Column.
Dear Sir, Please Explain Starting Setting Time Of Concrete.
What is the tollerence limit of Clear cover of Column and stirrup length???
What is cutting length of steel bar if column size 950×600
Reply:
Calculation of cutting length of stirrup for a column size 950×600:
Clear cover to column to be considered is 40 mm
Formula : Cutting Length = 2(a+b)+2xhook length -(3×90 degree bend + 2×135 degree bend)
Where a = 950-2×40 = 950-80 = 870
b = 600-2×40 = 600-80 = 520
hook length = 9xd where d is dia of bar
= 9×10 if you use 10 mm dia stirrup
deduction for bends = for 90 degree bend deduction is 2xd = 2×10
for 135 degree bend deduction is 3xd = 3×10
Therefore cutting length = 2(870+520)+2x9x10-(3x2x10+2x3x10)
= 2×1390+180-(60+60) = 2780+180-120 = 2840 mm = 2.84 m
Note : The above caluculation will only be the correct where so many persons use to calculate the same in so many different ways without having firm knowledge and hence if any body want to discuss about particularly calculation of cutting length of stirrup only you pl welcome to my mob 6002248094
Thanking you
Hey guys in above notes there are two pts, Chairs of minimum 12 mm diameter bars should be used.Minimum diameter of dowel bars should be 12 mm what does mean and minimum diameter of which dowel bar.?
why top and bottom extra bars provided in the beam at the junction??
Thank u very much.Really useful for civil engineer
why the column in L is the 300mm please describe me
Can anyone answer my query:
If we have 12 bars of 25 dia ( Vertical ) for column for 1st Floor. Then in second floor , the 4 Bars change to be from 25 dia to 20 Dia . What cutting length shall be payable for 1st Floor and what shall be payable for 2nd floor.
in 1st floor lap length will be calculate based on 25 dia; in 2nd floor lap length will be calculate based on 20 dia
it is correct
It’s very use full for junior site engineer
Thanks for giving such an useful information.
Please also describe about lap length in columns , beams,etc
Lap length is approximately 60d
d is the diameter of the reinforcement
sorry it lies between 45d and 55d
why we use 8 diam and 10 diam for ground slab
Please can anyone send to my email example of Steel Bars calculations using the M.S. Excel Sheet if you got any sample
I said really thanks..by heart….
Thanks for giving useful information
For the of 18ft – 14ft room what is the beam depth and reinforcement detail are required