Question

Marshall stability determines .......

• A. ductility
• B. flexibility
• C. utility
• D. grade of bitumen

Hint:

Marshall Stability evaluates a mix's resistance to deformation under load. The accompanying flow value reflects the mix's flexibility—crucial for long-lasting pavements.

Answer 1

The Correct Option is B

Step 1: Understanding Marshall Stability Test
The Marshall Stability Test is a standard test used in pavement design to determine the strength and performance characteristics of bituminous mixtures. It primarily evaluates two parameters:
- Stability: Maximum load the specimen can withstand before failure.
- Flow: The deformation corresponding to this maximum load.
Step 2: Interpretation
- High stability means the mixture can carry heavy loads without deforming excessively.
- The corresponding flow value gives an indication of the mixture’s flexibility.
Step 3: Relevance to Pavement Design
- A balanced value of stability and flow ensures that the mix is neither too brittle (which may crack) nor too soft (which may rut).
- Therefore, Marshall stability indirectly determines the flexibility of bituminous mixtures.
Step 4: Option Evaluation
- Ductility → relates to bitumen, not mix strength
- Flexibility → Correct interpretation of Marshall parameters
- Utility → Irrelevant in this technical context
- Grade of bitumen → Not measured by Marshall test