Bonded PT
- Stress transfer is through bond (require cement grouting)
- strain compatibility between strand and concrete
Very common in Australia, Middle East, and Europe
Unbonded PT
- stress transfer is through anchorage
- no grouting required
- no strain compatibility
- strand and concrete moves independently
Very common in North America
Mono strand system
- strands in tendon are stressed separately usually 1, 3 or 5 strands per tendon
Used in slabs or beams
Multi strand system
- strands in a tendon are stressed at the same time (16, 19, as much as 37 strands per tendon)
Used in bridges, and in buildings (transfer beams)
PT structures are used in
- slab on grade (for houses in expansive soil)
- Mat foundation (raft)
- parking structures
- flat plate
- bridges (Girder type, cable stay, suspension)
- silos
- water tanks
- walls (currently becoming common for shear walls in seismic areas)




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