Question

A uniformly distributed load intensity, w, acting on a simply supported prestressed concrete beam of span, L, producing a bending moment, M, at mid-span is to be balanced by a parabolic tendon with zero eccentricity at ends and eccentricity e, at mid-span. The prestressing force required depends on:

• A. W and e
• B. w and L
• C. L and e
• D. M and e

Answer 1

The correct option is D M and e




For fully counteract the effect of external
$M=Pecost\theta$
$P=\frac{M}{ecos\theta }$
Hence prestressing force P depends upon M & e.