Estimating Sheet

# Some useful civil engineering problems & their solutions on Doubly Reinforced Beam

Construction Software

Example 01: Determine the Number of 32-mm Steel Bars for Doubly-Reinforced Concrete Propped Beam.

Problem: There is a propped beam with length 8 m to withstand a total load of 28.8 kN/m. It is required to determine the steel reinforcement at the most vital section in bending.

The dimension of the cross section of the concrete beam is 400 mm x 600 mm containing an effective cover of 60 mm for the reinforcements. f’c = 21 MPa, fs = 140 MPa, n = 9. Find out the desired number of 32 mm ø tension bars and the number of 32 mm ø compression bars.

Example 02: Stress of Tension Steel, Stress of Compression Steel, and Stress of Concrete in Doubly Reinforced Beam.

Problem: A reinforced concrete beam section with dimension 300 mm × 600 m is reinforced with 4 - 28-mm-diameter tension steel at d = 536 mm and 2 - 28-mm-diameter compression steel at d' = 64 mm. The section has to undergo a bending moment of 150 kN•m. Utilize n = 9.

1. Determine the maximum stress in concrete.
2. Work out the stress in the compression steel.
3. Work out the stress in the tension steel.

### Also Read: How to design a double reinforced concrete beam

Example 03: Design of Steel Reinforcement of Concrete Beams with WSD Method

Detail guidelines for determining the desired steel reinforcements of beam with known Mmax and other beam properties with Working Stress Design method.

The calculation is done based on the following data :-