Question

In a flexible pavement, the minimum thickness of base material should be kept as ..........

• A. 20 cm
• B. 15 cm
• C. 10 cm
• D. 5 cm

Hint:

Always refer to the latest IRC:37 guidelines for pavement design, especially for updated traffic categories and layer thickness criteria.

Answer 1

The Correct Option is C

Step 1: Understand the base course in flexible pavements
Flexible pavements consist of multiple layers—surface course, base course, sub-base, and subgrade. The base course distributes load and provides structural support.
Step 2: IRC guidelines on base thickness
As per IRC:37-2018, the minimum thickness of the granular base course should be not less than 100 mm (i.e., 10 cm), especially for low to medium traffic categories.
Step 3: Option evaluation
- 20 cm and 15 cm → Acceptable but not minimum
- 10 cm → Correct minimum as per IRC
- 5 cm → Too thin, not acceptable
Step 4: Final Answer
Therefore, the minimum base thickness is 10 cm.