What should be done to indicate the degree of variation in a stockpile?

Drawing samples from separate areas of the pile is the appropriate method to indicate the degree of variation in a stockpile. Stockpiles can exhibit significant variability, influenced by factors such as material source, handling, and placement. By sampling from different sections, you capture a more comprehensive picture of the stockpile's overall characteristics, including potential differences in particle size, moisture content, and composition.

This strategy reflects the concept of spatial variability, ensuring that the assessment accounts for inconsistencies that might affect the quality of the materials. It minimizes the risk of overlooking variations that could arise in localized areas, providing a more representative analysis for decision-making.

Using a single sample from one large area would not adequately represent the entire stockpile, as it could reflect only the specific conditions of that area. Analyzing material for chemical composition might provide valuable information, but it would not suffice to capture the physical variability present in the pile. Relying on one expert's evaluation may introduce subjectivity and might not cover the full range of material properties.

Overall, sampling from various areas allows for a thorough understanding of the stockpile's diversity, which is essential for quality control in construction materials.