Which of the following is not the feature of Self Compacting Concrete? i. A minimum slump flow of 250 mm ii. Sufficient amount of fines (< 0.125 mm) preferably in the range of 400 – 600 kg/cm³ iii. High range of water reducing admixtures (HRWR) and viscosity modifiers (VMA) in appropriate dosage
- AOnly (i)Correct
- B(i) and (ii)
- C(ii) and (iii)
- D(i), (ii) and (iii)
Solution
Concept
Features of SCC
Step-by-step solution
1. SCC needs a slump flow of about 550–850 mm, not 250 mm, so (i) is not a feature. 2. It needs a high fines content (400–600 kg/m³) and HRWR/VMA admixtures.
Explanation
Only the slump-flow value in (i) is wrong.
Why the other options are wrong
(ii) and (iii) are features of SCC (the unit in (ii) is a typo for kg/m³).
Shortcut
SCC slump flow ≥ 550 mm.
Correct answer: A) Only (i)