# Things Site Engineers Must Know About Reinforcement and Steel Bars

Posted in Student Corner | Email This Post |*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

āLā 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 = d^{2}/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.*

holow buddies,am having the kind of confusion in rcc structure steel fixing.in that frm the given layout how can I predict myself which 1 type of steel bar should lay first for initiate the structure and further completion.how to get the

knowledge in that kind of rcc steel fixing works..give me some guidelines..

what the minimum nd maximum percetage of steel in column nd beam,slab….plz tell me guys

0-4% for Slab, 4-8% for beam, 8-12% for footing and 12-16% for column. the percentage is calculated in unit weight of steel i.e 7850. The result, which is calculated in this is for 1 m3 of concrete.

0.12% for slab & footing in case of deformed bars, 0.2% to 4% for beams, 0.8% to 6% for columns

it should be 0.6 to 8% of the column or beam or slab.

Why we not use bar in center of column

How may laps permitted in main and cross bars in a column footing.

Nice work.. Keep it up..!!

Can we Have 1.95m length of cantilever slabs on both side supporting by a beam with 8mm dia TMT bars @150mm C/C both sides (top and bottom).Please clarify.

plz tell me how i will find the cut length of steel in circular slab

U can try frm auto cadd I’n cutting length of circular slab.

what is spaceing in chair rod in rebar specification

how to calculate the steel rod diameter required for RCC beams

in a given drawing of steel reinforcement how to find out the main bars and distribution rods

in above notes there is point that Lapping is not allowed for the bars having diameters more than 36 mm. what does it mean i cannot understand this because every where lapping is must in rebar.

Because u cannot lap such a bigger dia bars, we can use anchorage bolts to lap them.

It should be welded befor going to making a joint

if we provide more laps in longitudinal reinforcement of deck slab then is it a problem?

in footing design main reinforcement or distributer steel which lies on bottom

Exactly where overlapping is taken for BEAM , COLUMNS, SLABS.

If the plain bar are used , the area of distribution reinforcement in slab should not be less then 0.12%, 0.15%, 0.18% 0.21, of the gross area of concrete plsss tell

Dear sir Please Explain Why We add one Extra Bar in Calculation Of BBS

hey guys , does any body know a calculation for alternative reinforcements . such as if we are using 12mm and 16mm s insted of using 20mm s , how many bars we has to use and how can we use them . any idea

Just calcuate equivalent area of the reinforcing bar to be used

Area of steel calculation to be done.

12 dia bar @ 150 mm spacing as per the drawing.but we do not have 12mm at site in that condition

we are going for higher dia (16mm)with area of steel calculation.

step:1

To find sapcing

Formula = d*d/s d1=12mm d2=16mm

s1=150mm s2=?

d1*d1/s1 = d2*d2/s2

12*12/150 =16*16/s2

s2=266.66 mm

Step:2

Area of steel calculation

Formula =3.14*d*d/4

3.14*12*12/4 = 3.14*16*16

113.04mm*mm = 200.96mm*mm

we have to divided by spacing

133.04/s1 =200.96/s2

133.04/150 = 200.96/266.66

0.7536 mm = 0.7536 mm

Hence the spacing the spacing calculation S2 is correct

Step : 3

For sample we are calculating for 4sqm (using 16 dia bar instead of 12mm)

12mm bar @ 150 mm spacing = 4000/150

=26.66 ..say 27 nos of 12mm bar @ 150mm spacing

16mm bar @ 266.66 mm spacing = 4000/266.66

=15.0003 …say 16 nos of 16mm bar @ 266.66 mm spacing

Thank you

lets say there is T12@100c/c to be replaced with T16 due to unavailability of T12.

so area of T12-113.04

area of T16-200.96

no. of T12 in 1 meter = (1000/100)+1 = 11nos.

area of 11T12 bars = (113.04*11)= 1243.44.

therefore no of T16 bars req = 1243.44/200.96 = 7

so the spacing of T16 bars =142.85mm. rounding to 140 c/c.

so T16 bars can be used 7-T16@140c/c

what is the gauge of binding wire normally using for Tying of reinforcement?

Can any plz tell me easy way to calculate Quantity of Steel for Raft Foundation