Consider the following statements regarding the concrete mix design : 1. It is to be compressive with strength of standard test specimens. 2. It is to be compiled with the durability requirements to accept the environment. 3. It is to be capable of mixed, transported, and compacted as efficiently as possible. Which of the above statements are correct ?
- A1 and 3 only
- B1, 2 and 3Correct
- C2 and 3 only
- D1 and 2 only
Solution
Concept
Objectives of mix design
Step-by-step solution
1. The mix must achieve the specified strength (statement 1). 2. It must meet durability requirements for the exposure (statement 2). 3. It must have the workability needed to be mixed, transported and compacted (statement 3).
Explanation
Mix design balances strength, durability, workability and economy, so all three statements are valid.
Why the other options are wrong
Each of the other options leaves out a design requirement.
Shortcut
Mix design: strength + durability + workability + economy.
Common mistake
Omitting durability.
Correct answer: B) 1, 2 and 3