Question

Fineness modulus of sand measures its. 
• [A.] Ratio of coarse and fine sand 
• [B.] Compressive and tensile strength of sand 
• [C.] Bulking of sand 
• [D.] Grading of sand as per particle size 
• [E.] Porosity of sand Choose the correct answer from the options given below :

• A. A and B
• B. C and E
• C. D
• D. A, B and C

Hint:

Fineness Modulus (FM):
• Indicates average particle size
• Obtained from sieve analysis
• Higher FM \(\Rightarrow\) coarser aggregate FM is important in concrete mix design and aggregate selection.

Answer 1

The Correct Option is C

Concept: Fineness Modulus (FM) is an empirical number used to indicate the average particle size and grading of aggregates such as sand. It is obtained from sieve analysis and helps determine whether sand is:
• Fine
• Medium
• Coarse Higher fineness modulus indicates coarser aggregate.

Step 1: Analyze statement A.
Fineness modulus does not directly measure the ratio of coarse and fine sand. Hence, statement A is incorrect.

Step 2: Analyze statement B.
Fineness modulus is unrelated to compressive or tensile strength. Hence, statement B is incorrect.

Step 3: Analyze statement C.
Bulking of sand depends on moisture content and is not measured by fineness modulus. Hence, statement C is incorrect.

Step 4: Analyze statement D.
Fineness modulus indicates the grading and average particle size distribution of sand. Hence, statement D is correct.

Step 5: Analyze statement E.
Porosity is not determined using fineness modulus. Hence, statement E is incorrect.

Step 6: Choose the correct option.
Fineness modulus measures grading of sand according to particle size. Therefore, the correct answer is: \[ {\text{(C) D}} \]