Question

Which one of the following is utilized to determine the long-term deformation of concrete under sustained loading?

• A. Creep
• B. Shrinkage
• C. Modulus of rupture
• D. Split tensile strength

Hint:

Think about which concrete property keeps changing with time even when the applied stress stays constant, not the ones tied to moisture loss or short-duration strength tests.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks which property of concrete is used to find its long-term deformation when a sustained (constant) load acts on it over time.

Step 2: Key Formula or Approach:
Concrete under sustained load deforms in two stages: an instantaneous elastic deformation right when the load is applied, and then a slow, additional deformation that keeps growing for months or years even though the load stays the same. This slow, time-dependent increase in strain under constant stress is called creep.

Step 3: Detailed Explanation:
Check each option one by one.
Creep is defined as the gradual increase in strain in concrete held under a constant sustained stress, over a long period of time (months to years). This is exactly the long-term deformation the question is asking about.
Shrinkage is a volume reduction that happens as moisture leaves the concrete during drying or as the cement paste hydrates and loses water. It happens whether or not any load is applied, so it is not a load-dependent deformation.
Modulus of rupture is the theoretical tensile stress at which a plain concrete beam fails in bending; it is a short-term strength property from a flexure test, not a deformation over time.
Split tensile strength is the indirect tensile strength of concrete found from a cylinder splitting test; again this is an instantaneous strength value, not a long-term deformation measure.
Since only creep describes deformation that keeps increasing with time under sustained load, it is the correct property.

Step 4: Final Answer:
The long-term deformation of concrete under sustained loading is measured through creep. \[ \boxed{\text{Creep}} \]