An unbonded tendon is usually a single 0.5 in, seven-wire strand of 270 ksi steel, greased and sheathed in plastic, with a fixed anchor at the dead end and a stressing anchor at the live end. Each one is jacked to about 33,000 lb and its elongation is measured against the calculated value, commonly within 7 percent. Once the numbers are approved, the tails are cut and the stressing pockets are grouted.
Measure every tendon on the east bay and flag any elongation off by more than seven percent before anybody cuts tails.
Also heard as
- strand
- PT cable
- cable
Related terms
PT
Post-tensioning: reinforcing concrete with steel tendons that are stretched tight after the concrete hardens.
Maturity method
Estimating in-place concrete strength from its temperature history, recorded by sensors cast into the pour.
Rebar
Deformed steel bar cast into concrete to carry the tension that plain concrete cannot.