Civil Engineering Reference
In-Depth Information
Figure 19.11
(
continued
)
The deflections due to the tendon stresses will change with time. First of all, the
losses in stress in the prestress tendons will reduce the negative moments they produce
and thus the upward deflections. On the other hand, the long-term compressive stresses in
the bottom of the beam due to the prestress negative moments will cause creep and there-
fore increase the upward deflections.
In addition to the deflections caused by the tendon stresses, there are deflections due
to the beam's own weight and due to the additional dead and live loads subsequently
