Which statement is true about splitting large samples using methods?

• A. Draindown at production temperatures should not exceed 3%.
• B. Surfaces that will be exposed to hot mix asphalt should be coated with petroleum based release agents prior to use.
• C. In the incremental method, the entire sample should be turned over itself at least three times.
• D. When samples are large, it is recommended that they be split using mechanical methods.

Answer: (D)

When you’re dealing with large asphalt samples, the goal is to get representative sub-samples without bias or damage, and the best way to do that is with mechanical splitting. Mechanical methods, like a sample splitter or riffle box, randomize the portioning and give you sub-samples of equal or known masses. This keeps the test results reliable by reducing human error and uneven sampling that can happen with manual splitting or handling large chunks.

The other statements don’t address splitting large samples. Draindown limits pertain to how much moisture or oil can separate from the mix during production, not how you subdivide a bulk sample. Using petroleum-based release agents on surfaces that will contact hot mix would risk contaminating the sample and affecting test results. The described rule about turning the entire sample over three times in an incremental method isn’t a standard or universal guideline for splitting large samples, so it doesn’t establish a correct principle for this practice.