After decantation, what should be done with material on the 75-μm ( #200 ) sieve and any remaining fines on the larger sieve?

• A. Return them to the coarse fraction for disposal
• B. Dry them in a separate oven
• C. Discard them
• D. Return them to the sample for drying

Answer: (D)

After decantation, the fine material that remains on the 75-μm (No. 200) sieve and any remaining fines on the larger sieves are still part of the sample and must be dried with the rest of the material. Return them to the sample and dry the whole thing to a constant mass so the final results reflect the complete sample, including all fines. Drying them separately or discarding them would introduce bias and loss of material, distorting the gradation and moisture data. The correct practice is to keep all retained material together and dry it in the same oven to ensure consistent, accurate results.