The members in which the entire cross-section of concrete has a uniform compressive pressure is called
- AAxial prestressingCorrect
- BConcordant prestressing
- CEccentric prestressing
- DNon-distortional prestressing
Solution
Concept
When the prestressing force acts at the centroid of the section, the whole section gets uniform compressive stress.
Formula
σ = P/A
Step-by-step solution
1. Uniform compressive stress over the full section needs zero eccentricity. 2. A force at the centroid (e = 0) gives σ = P/A, the same at every point. 3. This is called axial (concentric) prestressing. 4. Answer is (A).
Explanation
In axial prestressing the tendon force acts along the centroidal axis. So the stress is P/A everywhere and the whole section is under uniform compression. No bending stress is produced.
Why the other options are wrong
B: Concordant prestressing means a tendon profile in an indeterminate structure that causes no secondary moments, not uniform stress. C: Eccentric prestressing gives P/A ± Pe/Z, so stress varies across the depth. D: Non-distortional prestressing means the prestress causes no deflection or distortion, not uniform compression.
Shortcut
Uniform stress means e = 0, so the answer is axial (concentric) prestressing.
Common mistake
Confusing concordant prestressing with uniform stress. Concordant relates to secondary moments only.
Correct answer: A) Axial prestressing