Which statement is true about handling large samples when splitting?

• A. In the incremental method, the entire sample should be turned over itself at least three times.
• B. When samples are large, it is recommended that they be split using mechanical methods.
• C. In the quartering method, the pile should be flattened so that the diameter is four to eight times the thickness of the pile.
• D. The type B mechanical splitter used for coarse aggregate should have at least eight chutes, which are set to be at least 50% wider than the largest aggregate particle being split.

Answer: (B)

When you’re dealing with a large sample, the goal is to obtain a small portion that truly represents the whole. Mechanical splitting is the best approach here because it produces a random, uniform subsample quickly and consistently, reducing the chance that handling bias or uneven distribution will skew the test results. Manual methods can introduce bias through uneven mixing, layering, or inconsistent cuts, especially with big samples.

The incremental method’s rule about turning the entire sample over a specific number of times isn’t a universal standard—it's about achieving thorough mixing, but the exact number of passes isn’t fixed across procedures. The quartering method’s guidance to flatten the pile so its diameter is a certain multiple of its thickness is a specific handling guideline for that method, not a blanket rule for all large-sample splitting. The requirement about a particular Type B mechanical splitter (eight chutes and a specific width relative to the largest particle) is equipment-specific and may not apply to every lab setup. Therefore, mechanical splitting of large samples is the general, widely recommended practice.