What fine aggregate reduction method involves obtaining increments in a random X pattern?

The method that involves obtaining increments in a random X pattern is the mini stockpile method. This technique is designed to ensure a representative sample of fine aggregate by allowing for random collection across a defined area. The random X pattern helps in achieving a more uniform representation of the material, minimizing bias that could occur if samples were taken from a single point or area.

In practical application, the mini stockpile method entails creating a small pile of aggregate material from which samples can be taken to get an accurate percentage of the fine aggregates present. This randomized approach aids in reducing variability in the sample to ensure the integrity and quality of the analysis conducted on the materials.

The other methods, such as the mechanical splitter, clam shell, and randomized pile, do not utilize a systematic random pattern for collection and instead rely on different approaches which may not achieve the same level of randomness or representative sampling as the mini stockpile method does.