Which set correctly identifies the three types of aggregate?

• A. Synthetic, Natural, and Processed.
• B. Natural, Processed, and Synthetic.
• C. Organic, Recycled, and Composite.
• D. Primary, Secondary, and Tertiary.

Answer: (B)

Aggregates are categorized by their origin and how they’re produced. Natural aggregates come directly from natural deposits with minimal processing, like gravel or sand mined from the earth. Processed aggregates come from those natural materials but have been crushed, screened, and sized to meet specific gradation and performance requirements. Synthetic aggregates are manufactured materials created specifically for use as aggregate, designed to achieve particular properties such as strength, density, or durability.

This three-way classification—natural, processed, and synthetic—captures the main ways asphalt aggregates are obtained and prepared, which is why it’s the correct set.