1- RCC drawings so that you can find out the following values from the drawing
Length of the element
Cross-section
No of bars
Type of bars
Spacing between the bars.
Lap length ( horizontal/vertical)
Development length
Click Here To See The Difference Between Development Length And Lapping Length
Covers for footing/column/beam/slab.
2- Calculate the cutting length of the bars
( total length – covers on both sides)+ development length.
Click Here To See Calculate Cutting Length Of Bent Up Bar In Slab
3- Formula
W = N*CL*U
W: Weight of reinforcement
N: No of bars
CL: cutting length
U: Unit weight
You can find out Unit weight from charts or the formula :
U= D*D/162.
D= Diameter of bar (in mm)
General steel requirement for different RCC members in kilogram per cubic meter
Column footings 75 kg/m3
Grade beams 100 kg/m3
Plinth beams 125 kg/m3
Main beams above 6m 250 kg/m3
Columns 225 kg/m3
Lintel beam 125 kg/m3
Sunshades 60 kg/m3
Canopy slab up to 2.0 m span 125 kg/m3
Staircase waist slab 150 kg/m3
Roof slab
(a) One way slab 80 kg/m3
(b) Two-way slab 100 kg/m3
(c) Square slab – 4m to 6m size 150 kg/m3
Click Here To See Bar Bending Schedule [BBS] Estimate Of Steel In Building Construction