Post-tensioned concrete is a complex product. This section deals mainly with
questions related
to post-tensioned, slab-on-grade foundations and then only scratches the
surface. For more specific
information or a consultation please contact us directly.
What is prestressed concrete?
Concrete reinforced with steel tendons under tension.
What is post-tensioned,
prestressed concrete?
Concrete that is prestressed by
tensioning it's tendons after it has been previously cast and
cured.
What are post-tensioning tendons?
Very high tensile strength, twisted
seven strand steel cables (prestressing strand) encased in a protective jacket with a
lubricant/preservative and assembled with an anchor at each end to hold
them under tension.
What are post-tensioning anchors?
Cast steel end-fittings with internal
grippers that are applied to each end of a tendon to retain its tension
and transfer that force to the concrete.
How are the tendons installed?
The tendons are placed in the concrete
forms according to an engineered plan and with one end protruding externally
for the purpose of elongating with a jack.
How are the tendons tensioned?
A hydraulic jack is fitted to the
jacking end of each tendon and against its anchor. When jacked,
the tendon is elongated to a specified force and then locked off to
retain that force.
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