-
A concrete beam pre-stressed with a parabolic tendon is shown in the sketch. The eccentricity of the tendon is measured from the centroid of the cross-section. The applied pre-stressing force at service is 1620 kN. The uniformly distributed load of 45 kN/m includes the self-weight.
The stress (in N/mm2) in the bottom fibre at mid-span is
-
- tensile 2.90
- compressive 2.90
- tensile 4.32
- compressive 4.32
Correct Option: B
Total stress bottom,
| σb = | + | - | ||||
| A | Zb | Zb |
| I = | 12 |
| = | = 4687500 mm2 | 6 |
Zb = Zt.
= 2.93
