Post-Tensioning-Test Questions and
Answers.
When should discrepancies in material deliveries be reported? - Answer Immediately upon
discovery
What should be used to unload bundles of fabricated tendons? - Answer Nylon slings
Define prestressed concrete: - Answer Concrete in which internal stresses are induced by
means of prestressing steel tendons
Which factors determine the amount of uplift force in a post-tensioned member? - Answer
Quantity of prestressing steel and the profile of the tendons
What does the term KSI stand for? - Answer 1000 pounds per square inch
Which two factors are used to determine Minimum Ultimate Tensile Strength of prestressing
steel? - Answer The jacking force and the grade of the prestressing steel
Why is it important to understand what the yield strength of the prestressing steel is? - Answer
Because that is the force at which the tendons will break
What would the jacking force be for a 0.60" diameter - grade 270 KSI strand with a cross
sectional area of 0.217 square inches? - Answer 46.9 KIPS
Use the following factors to calculate the approximate elongation of a tendon:
Prestress force = 41.0 KIPS
Length of the prestressing steel = 600 inches
Area of prestressing steel = 0.217 square inches
E factor (modulus of elasticity) = 28,500 KSI
[PxL/AxE] - Answer 4 inches
What is the one factor that the post-tensioning installer can control to reduce potential
elongation variances? - Answer Friction loss due to the tendons profile
, On a structural plan, the engineer has called out Fe in a beam as 482.4 KIPS. This project is using
1/2" diameter - grade 270 KSI strand with a cross sectional area of 0.153 square inches. How
many tendons would you expect to see in this beam? - Answer 12 tendons
In reviewing the Post-Tensioning Installation Drawings, you notice that the number of tendons
called out on the drawings does not match the number of tendons shown by the symbols that
represent the tendons quantities. You should: - Answer Notify the general contractor and the
post-tensioning supplier for clarification prior to proceeding
On the Tendon Fabrication Sheets, the graphical depiction of a tendon is <~~>~> (those are
arrows). When shipped to the job, this coiled tendon would have: - Answer Only one
intermediate-end anchor threaded on the tendon
What size slab-bolster would you use at a tendons low point to achieve a CGS of 1" when using
1/2" diameter strand? - Answer 3/4" slab-bolster
At the tendon's high point, the structural plans call for a CGS of 8" in a 10" slab. What size chair
would be used if you are installing a single layer of 1/2" diameter strand with a #4 support bar?
- Answer 7 1/4" chair
Which best explains the meaning of CGS? - Answer The distance from the bottom of the slab
to the center of a strand or bundle of strands
In case of a conflict between the rebar heights and the tendons heights, you should: - Answer
Notify the general contractor and post- tensioning supplier for additional instructions prior to
proceeding
As long as the levels are identical, it is okay to use material labeled for level 3 on level 2 without
notifying anyone. - Answer False
All of the loose wedges, shipped to the job for stressing, can be used anywhere on the project. -
Answer False
What cannot be found on a prestressing steel mill certificate? - Answer Jacking force
The post-tensioning supplier should provide a calibration chart for each set of stressing
equipment shipped to the project. - Answer True
When comparing the required jacking force listed on the calibration charts to the jacking force
marked on the gauge, you notice that the charts say 5400 psi, but the gauge says 5500 psi. You
should: - Answer Do not use the equipment until you receive clarification from the supplier
Answers.
When should discrepancies in material deliveries be reported? - Answer Immediately upon
discovery
What should be used to unload bundles of fabricated tendons? - Answer Nylon slings
Define prestressed concrete: - Answer Concrete in which internal stresses are induced by
means of prestressing steel tendons
Which factors determine the amount of uplift force in a post-tensioned member? - Answer
Quantity of prestressing steel and the profile of the tendons
What does the term KSI stand for? - Answer 1000 pounds per square inch
Which two factors are used to determine Minimum Ultimate Tensile Strength of prestressing
steel? - Answer The jacking force and the grade of the prestressing steel
Why is it important to understand what the yield strength of the prestressing steel is? - Answer
Because that is the force at which the tendons will break
What would the jacking force be for a 0.60" diameter - grade 270 KSI strand with a cross
sectional area of 0.217 square inches? - Answer 46.9 KIPS
Use the following factors to calculate the approximate elongation of a tendon:
Prestress force = 41.0 KIPS
Length of the prestressing steel = 600 inches
Area of prestressing steel = 0.217 square inches
E factor (modulus of elasticity) = 28,500 KSI
[PxL/AxE] - Answer 4 inches
What is the one factor that the post-tensioning installer can control to reduce potential
elongation variances? - Answer Friction loss due to the tendons profile
, On a structural plan, the engineer has called out Fe in a beam as 482.4 KIPS. This project is using
1/2" diameter - grade 270 KSI strand with a cross sectional area of 0.153 square inches. How
many tendons would you expect to see in this beam? - Answer 12 tendons
In reviewing the Post-Tensioning Installation Drawings, you notice that the number of tendons
called out on the drawings does not match the number of tendons shown by the symbols that
represent the tendons quantities. You should: - Answer Notify the general contractor and the
post-tensioning supplier for clarification prior to proceeding
On the Tendon Fabrication Sheets, the graphical depiction of a tendon is <~~>~> (those are
arrows). When shipped to the job, this coiled tendon would have: - Answer Only one
intermediate-end anchor threaded on the tendon
What size slab-bolster would you use at a tendons low point to achieve a CGS of 1" when using
1/2" diameter strand? - Answer 3/4" slab-bolster
At the tendon's high point, the structural plans call for a CGS of 8" in a 10" slab. What size chair
would be used if you are installing a single layer of 1/2" diameter strand with a #4 support bar?
- Answer 7 1/4" chair
Which best explains the meaning of CGS? - Answer The distance from the bottom of the slab
to the center of a strand or bundle of strands
In case of a conflict between the rebar heights and the tendons heights, you should: - Answer
Notify the general contractor and post- tensioning supplier for additional instructions prior to
proceeding
As long as the levels are identical, it is okay to use material labeled for level 3 on level 2 without
notifying anyone. - Answer False
All of the loose wedges, shipped to the job for stressing, can be used anywhere on the project. -
Answer False
What cannot be found on a prestressing steel mill certificate? - Answer Jacking force
The post-tensioning supplier should provide a calibration chart for each set of stressing
equipment shipped to the project. - Answer True
When comparing the required jacking force listed on the calibration charts to the jacking force
marked on the gauge, you notice that the charts say 5400 psi, but the gauge says 5500 psi. You
should: - Answer Do not use the equipment until you receive clarification from the supplier
