In stockpile sampling, what is done to material before load out?

Before loading out material from a stockpile, remixing is a critical process to ensure that the material meets the specified gradation. Gradation refers to the distribution of different particle sizes within the aggregate, which is vital for achieving the desired properties of the final mixture, such as density, workability, and strength.

When aggregates are stockpiled, they can segregate, meaning that larger or smaller particles may settle differently due to gravity or other factors. By remixing the stockpile, the technician ensures a uniform blend of aggregate sizes, which helps achieve the optimal gradation specified for the project. This quality control measure is essential to maintain consistency and performance in the final hot mix asphalt or concrete.

Other options involve processes that are important but do not address the crucial step necessary for meeting gradation specifications prior to load-out:

• Drying and weighing aggregates is typically performed for moisture content testing but does not address gradation.

• Storing samples for testing is standard practice but does not involve any material preparation for immediate use.

• Coating materials may be relevant for preservation under certain conditions, but it is not routinely done strictly for preparation before load-out.

Therefore, remixing is fundamental in ensuring material quality and compliance with project requirements.