Extreme fiber stresses at the mid span section of the beam
A pre-stressed concrete beam, of cross section 300 mm x 500 mm and 8 m span, is pre-stressed with a parabolic tendon having a pre-stressing force of 2000 KN. The tendon has a sag of 150 mm at the mid span. The eccentricity of tendon at the ends of beam is zero. Find the extreme fiber stresses at the mid span section of the beam using the load balancing concept if it is subjected to :
(a) A total UDL of 300 kN, and
(b) A total UDL of 350 kN.