Example 01: Finding the Number of Steel Bars of Singly-reinforced Concrete Beam

A reinforced concrete cantilever beam 4 m long has a cross-sectional dimensions of 400 mm by 750 mm. It is to carry a superimposed load of 29.05 kN/m including its own weight. The steel reinforcement has an effective depth of 685 mm. Use f’c = 21 MPa, fs = 165 MPa, and n = 9. Determine the required number of 28 mm ø reinforcing bars using Working Stress Design method.