(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.

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

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

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

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) #8 50 #10 78.5 #12 113 #16 201 #20 314 #25 491 #32 804

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 x1.25 = 25 Cantilever = 7 x1.25 = 8 Continuous = 26 x 1.25 =32 Two Way ( Short span to be considered) Simply Supported = 35 Continuous (Restrained) = 40

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

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

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

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.