As per AASHTO soil classification, group index is applicable for which of the following group?
- AA-1
- BA-2
- CA-3
- DA-4Correct
Solution
Concept
Group index
Step-by-step solution
1. Group index is not applicable to A-1-a, A-1-b, A-3, A-2-4 and A-2-5. 2. It applies to A-4 to A-7 and A-2-6, A-2-7.
Explanation
A-4 is among the groups where GI is calculated.
Why the other options are wrong
A-1 and A-3 have GI = 0; A-2 subgroups vary.
Shortcut
GI for A-4 to A-7.
Correct answer: D) A-4