What are requirements of good aggregate?

Good aggregate should possess several key characteristics, including appropriate size and grading to ensure proper compaction and stability in concrete or asphalt mixes. It should have a low absorption rate and minimal porosity to reduce water uptake and enhance durability. Additionally, good aggregate must be free from impurities like clay, silt, and organic materials, which can adversely affect the strength and bonding of the final product. Finally, it should exhibit sufficient hardness and resistance to weathering to maintain structural integrity over time.