Deflections of PSC Beams

Q. What is the allowable upward deflection in a prestress concrete member under serviceability limit state condition?

1. Span/250
2. Span/300
3. Span/350
4. Span/500

Q. A simply supported post-tensioned prestressed concrete beam of span $L$ is prestressed by a straight tendon at a uniform eccentricity 'e' below the centroidal axis. If the magnitude of prestressing force is $P$ and flexural rigidity of beam is $EI$, the maximum central deflection of the beam is

1. $\frac{Pe{L}^2}{8EI}$ (downwards)
2. $\frac{Pe{L}^2}{48EI}$ (upwards)
3. $\frac{Pe{L}^3}{8EI}$ (upwards)
4. $\frac{Pe{L}^2}{8EI}$ (upwards)