Question

High strength/high grade concrete is preferred for pre-stressed concrete for controlling

• A. Ductility
• B. Brittleness
• C. Shrinkage
• D. Creep

Hint:

High-strength concrete in prestressed members helps reduce \[ \boxed{ \text{Creep} \quad\text{and}\quad \text{Shrinkage losses}. } \]

Answer 1

The Correct Option is D

Step 1: Losses in prestressed concrete.
A prestressed member loses some of its initial prestressing force over time. Part of this loss comes from elastic shortening and anchorage slip right at transfer, and part comes from long term effects such as shrinkage, creep and relaxation of steel.
Step 2: Why creep matters most here.
Creep is the slow, continued shortening of concrete under sustained compressive stress, and this shortening directly relaxes the tension held in the strands, eating into the prestress force year after year. A weaker, lower grade concrete creeps more under the same stress.
Step 3: Why high strength concrete helps.
Using high strength concrete keeps the sustained stress low relative to its capacity, which keeps the creep strain small, so the prestress force is preserved much better over the life of the member.
\[ \boxed{\text{Creep}} \]