Where are aggregates commonly produced from?

• A. Quarries and gravel sources
• B. Oceanic reefs
• C. Forest soils
• D. Recycled glass only

Answer: (A)

Aggregates used in asphalt come from quarried rock and natural gravel deposits. These sources provide hard, durable material that can be crushed to the required coarse and fine sizes and meet the performance specifications for strength, wear resistance, and weather durability. Oceanic reefs aren’t typical sources because they bring variability and contaminants and raise environmental concerns, making consistent quality harder to achieve. Forest soils lack the mechanical properties needed for pavement and can introduce organic matter that undermines performance. Recycled glass isn’t the standard primary source, though it can be used as a supplementary material in some mixes; it doesn’t replace the need for traditional quarried and gravel aggregates.