Guide to design of Singly reinforced Sections | Building Construction
For the “design of Singly reinforced sections” article series, we have covered the following:
- Basic definitions and formulas
- Understanding stresses and modular ratios
- Assumptions for singly reinforced sections
- Design procedure for Singly reinforced section – I
- Solved Numericals for Singly reinforced beam | Method I
- Design of Singly reinforced sections | Design Method 2
- Solved Numericals for Singly reinforced beam | Method 2
- Moment of Resistance for Singly reinforced sections
- Solved numerical example | Moment of resistance
- Solved numerical example 2 | Guide to singly reinforced sections
Numerical Problem
Determine the following:
a) The position of the neutral axis
b) Lever arm
c) Moment of resistance
d) Percentage of steel
(For a rectangular beam section of width b mm and effective depth d mm. Take σcbc = 5 N/mm2, σst = 140 N/mm2, m = 18.66
To find Neutral Axis (NA)
σcbc /(σst/m) = xc/(d – xc)
5/(140/18.66) = xc/(d – xc)
Therefore, xc = 0.399d mm= 0.4dmm
To find lever arm
z = d – xc/3
= d – 0.4d/3
= 0.867dmm
= 0.87d mm
To find Moment of resistance
Mr = C x z
= bxc (σcbc/2)z
= b (0.4d)(5/2)(0.87d)
= 0.87 bd2 N-mm
To find the percentage of steel
Equating, C = T
bxc.σcbc/2 = Ast. σst
Therefore, Ast = bxc.σcbc/2 σst
= [b (0.4d)(5/2)]/140
= bd/140 mm2
Pt = Ast. 100/bd
= (bd/140) x (100/bd)
= 0.71
Thanks Benjujk for your effort. Please provide sample of one complete multistoried building design using working stress method.
Thanx. That time i’m doing diploma in civil engineering
hi
plz can you provide me one 3 storey industrial RCC design with loading details.
thank you
A single support R.C C beam 250mm wide and 450mm deep is reinforced with 4_18mm diameter basis.design and shear reinforced of span 5m if m20 grade of concrete and Fe 415 steel is used and beam is subjected to a shear force of 150kn at sevice state…plzz ans yhis