Bar Bending Schedule For Slab And Estimation Of Steel Reinforcement In Slab
Bar Bending schedule plays a vital role in finding the quantities of reinforcement in structure. In order to find out the Bar bending schedule for slab or steel reinforcement in Slab, I recommend you to learn Basics of Bar Bending schedule and how to adopt concrete cover for different components of a building.
- Bar Bending Schedule for Slab:-
- Quantity of Reinforcement (Steel) required for Slab Or Bar Bending Schedule for Slab:-
- Floor Slab – 1 (Two-Way Slab):-
- For Floor slab -2 (One way slab) :-
Bar Bending Schedule for Slab:-
There are 16 different types of slabs in construction. Well, the thickness of slab generally varies between 4″ to 8″. We generally adopt 6″ (0.15m) slab thickness. For occasionally heavy loads we adopt 8″ and above thickness slabs.
Quantity of Reinforcement (Steel) required for Slab Or Bar Bending Schedule for Slab:-
In this post, I am finding out the Estimation of Steel reinforcement required for a Slab to work on this I considered a plan as shown below.
Primarily slabs are classified into two types One-way Slab and Two-way slab to know more about the differences refer here.
In one-way slab, Main bars are provided in shorter direction (Cranked bars) and distribution bars are provided in Longer direction (Straight bars). Whereas in Two-way slab Main bars (cranked bars) are provided in both directions. Usually, the Two-way slab is adopted when the length and width of the slab is more than 4m.
Well to make you perfect in Bar Bending Schedule for a slab, I am considering a One-way slab and two way slab as shown in the figure. Main bars and distribution bars are provided in the One-way slab. In two way slab, distribution bars are provided in both sides of slab.
Distribution bars:- These bars are straight bars.
Main bars:- These bars are cranked bars. Main bars are cranked at an angle of 45 Degree with the length of 0.42D
Where, D = Depth of Slab- Top cover – Bottom cover
Extra Bars:- The extra bar is provided at the bottom of Cranked bars to maintain the framework of the slab.
The length of Extra bar is L/4.
Steps to calculate the Reinforcement required for Slab:-
- Deduct the cover for finding length of bar.
- Evaluate the length of the distribution bar
- Calculate the Value of ‘D’ (Depth of slab- Top cover- Bottom cover)
- Find out the No. of Bars
- Compute the Total wt of steel required for slab reinforcement.
Dia of bars = 10mm , Spacing between bars = 0.10m , Depth of Slab = 0.15m
Floor Slab – 1 (Two-Way Slab):-
Bars along X Axis:-
Bars along Y Axis:-
Total wt of Bars = 150.285+150.091 = 300.376Kgs
For Floor slab -2 (One way slab) :-
As per the above figure Floor slab -2 is a One way slab. In this kind of slab Mains bars (cranked bars) are provided in shorter direction hence there is no need of calculating the crank bar length in Y-direction (from fig). Evaluate the length of Bar as given in the figure by deducting the covering length. Whereas in X Direction Crank bar length is considered.