Question

$\text{(A):}$ Losses in prestress in pre-tensioned beams are more than the losses in post-tensioned beams.
$\text{(R):}$ This is partially due to the effect of elastic shortening.

• A. both A and R are true and R is the correct explanation of A
• B. both A and R are true but R is not a correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Answer 1

The correct option is A both A and R are true and R is the correct explanation of A

Loss in pre-tensioned member is due to elastic deformation of concrete, relaxation of steel, shrinkage and creep of concrete which is equal to almost 20% of prestress. The loss due to elastic shortening does not occur in post tensioned member so losses are limited to 15% of initial prestress.