Question

Maximum size of aggregate in base course is ........

• A. 25 mm
• B. 50 mm
• C. 40 mm
• D. 30 mm

Hint:

For base courses in flexible pavements, the IRC recommends a maximum aggregate size of 50 mm to ensure effective load transfer and structural stability.

Answer 1

The Correct Option is B

Step 1: Understanding base course function
The base course in a flexible pavement lies directly below the surface or binder course and distributes traffic loads to the sub-base or subgrade.
Step 2: Aggregate size standards
According to the Indian Roads Congress (IRC) and Ministry of Road Transport and Highways (MoRTH) specifications: - The maximum size of aggregates for the base course is typically limited to 50 mm. - This ensures adequate interlocking and load distribution without segregation during laying.
Step 3: Comparison with options
- 25 mm and 30 mm → more common for surface or binder courses.
- 40 mm → may be used in some sub-base works but not the typical max for base.
- 50 mm → correct and standard maximum for base course.