Statement
A single reinforced rectangular beam has a width of 11” and effective depth of 18”. If f’c = 3ksi and fy is 40ksi. Calculate the moment capacity Mn, if As = 5in2
Given
- Width of beam = b = 11”
- Effective depth of reinforced concrete beam = d = 18”
- f’c = 3 Ksi
- Fy = 40 ksi
- As = 5in2
Required
Moment capacity of the reinforced concrete beam = ?
Solution
Given problem is the analysis case. For understanding the solution, one must should have ACI 318M-08 building code.
find steel ratio by using formula defined by ACI 318M-08
Ρ = AS/bd = 5/(11*18) = 0.025
Now find respective value of “R” from Graph A.1a (Moment capacity of Rectangular beam)
R = 800 Psi
Mn =2851.2 K-in.