1. (i) proper arrangement of reinforcing bars and
Beams & Slabs
Breadth of the beam b
(i) proper arrangement of reinforcing bars and
(ii) architectural considerations.
b <= column width, or width of the wall
Practical aspects b as 200, 230, 250 and 300 mm.
b /D = 0.5 and 0.67.

2. Effective Depth d (ii) deflection of the beam. d is based on L/d ratio
(i) the strength requirements of bending moment and shear force,
(ii) deflection of the beam.
d is based on L/d ratio
For Simply Supported beams
1M span = 70mm or L/d = 15;may be assumed

3. Tension steel Ast
Provide Longitudinal bars
(i) Ast should provide the required moment of resistance = factored moment Mu
(ii) should satisfy minimum and maximum pt requirements
(iii) Ast (min) -
As/bd = 0.85/fy
(iv) Ast (max) -
As = 0.04bD

4. Compression steel Asc
Provide Longitudinal bars
(i) Asc should provide the required moment of resistance = factored moment Mu
(ii) should satisfy maximum pc requirements
(iii) Asc (max) -
As = 0.04bD

5. Concrete Grade, Steel Grade, ReBar Dia (i) Concrete: Minimum: M20
(ii) Steel: Fe250,Fe415,Fe500
(iii) Longitudinal Re Bars: #12, #16, #20,#25,#32
Dia Area (mm2) # # # # # # #

6. General Design Considerations
L/d ratio
Since slabs are provided with less pt ( 0.3%), higher values are assumed, kt = 1.25
One way
Simply supported Slabs = 20 x = 25
Cantilever = 7 x = 8
Continuous = 26 x =32
Two Way ( Short span to be considered)
Simply Supported = 35
Continuous (Restrained) = 40

7. 3. Clear Cover=20 mm (Table 16A) 4. Rebar Dia: #8,#10,#12
2. Minimum Slab Thickness = 100mm. (practical)
3. Clear Cover=20 mm (Table 16A)
4. Rebar Dia: #8,#10,#12
5. Maximum Rebar Dia = (1/8) xD
6. Minimum Ast
0.12% of Total C/S area – HYSD
0.15% of Total C/S area – MS

8. 7. Maximum Spacing Main Reinforcement: < Min(3d or 300 mm)
Temperature and shrinkage reinforcement (Distribution)
< Min(5d or 450 mm)
placed perpendicular to main bars
above main bars for sagging moments
below main bars for Hogging moments

9. Bar Marks
8. Rebar Shapes
Straight Bars at Bottom for Sagging Moments (CONTINUOUS EDGE)
Straight Bars at Top for Hogging moments (Continuous Edge)
Straight bars with Hooks (Discontinuous Edge)
Bent-up bars used to resist both sagging and Hogging moments. (Not much preferred)
U -bars used for corner reinforcement in two way restrained slabs

10. 9. Bar marks
Bar marks are short lines drawn at 450 at the ends of rebars
They are used to distinguish rebar lines from other lines in drawing.
Also the directions indicate the positioning of rebar's in slabs - whether to be placed at bottom or at top.