Prestressed structure is the one whose overall integrity, stability and security depend, primarily, on a prestressing. Prestressing means the intentional creation of permanent stresses in a structure for the purpose of improving its performance under various service conditions.
There are the following basic types of prestressing:
- Precompression (mostly, with the own weight of a structure)
- Pretensioning with high-strength embedded tendons
- Post-tensioning with high-strength bonded or unbonded tendons
Today, the concept of prestressed structure is widely employed in design of buildings, underground structures, TV towers, power stations, floating storage and offshore facilities, nuclear reactor vessels, and numerous kinds of bridge systems.
The idea of prestressing was, apparently, familiar to the ancient Rome architects; the tall attic wall of the Colosseum works as a stabilizing device for the wall piers beneath.