56 Damage to concrete structures
When the cable is positioned correctly, it will generate upward forces
in the concrete beam, counteracting the downward forces provided by
self-weight of the beam or by live load. This is how the prestressed cable
increases the load bearing capacity of the concrete beam, compensating for
(part of) the external loading, and making sure that no (or only limited)
tensile stresses occur in the concrete.
Figure 3.6 Reinforcement corrosion in case of insufficient cover thickness.
Insufficient cover
due to shift of
reinforcement cage
Figure 3.5 Insufficient cover thickness.