Which of the following best lists the tests used to establish aggregate stability?

Which of the following best lists the tests used to establish aggregate stability?

• A. Bulk density, Proctor compaction, Atterberg limits, permeability
• B. Bulk specific gravity, LA abrasion, sulfate, crushing, freeze-thaw, and mineral hardness
• C. LA abrasion, sulfate, and pH measurements
• D. Shear strength, bearing capacity, compaction tests

Answer: (B)

Aggregate stability is about how well an aggregate resists breakdown under real-world conditions, including mechanical wear, chemical attack, and weathering. To judge this, you need a set of tests that cover multiple durability pathways. Bulk specific gravity gives a baseline density and porosity context that influences how the material behaves under load and moisture. The Los Angeles abrasion test simulates surface wear and fragmentation due to grinding action, mimicking traffic and handling. Sulfate exposure tests assess chemical durability, since sulfates can cause weakening or degradation of the aggregate matrix. A crushing test measures resistance to crushing under compressive forces, indicating how the material will perform under load. Freeze-thaw testing reproduces cycles of wetting and freezing that can crack and spall rocks in cold climates. Mineral hardness reflects inherent toughness and resistance to surface wear. Together, these tests provide a comprehensive view of an aggregate’s ability to stay intact in service, which is why this set is the best choice. Other options mix tests that don’t directly target aggregate durability or omit key durability factors like chemical and freeze-thaw resistance, so they don’t give a complete picture of stability.

Aggregate stability is about how well an aggregate resists breakdown under real-world conditions, including mechanical wear, chemical attack, and weathering. To judge this, you need a set of tests that cover multiple durability pathways. Bulk specific gravity gives a baseline density and porosity context that influences how the material behaves under load and moisture. The Los Angeles abrasion test simulates surface wear and fragmentation due to grinding action, mimicking traffic and handling. Sulfate exposure tests assess chemical durability, since sulfates can cause weakening or degradation of the aggregate matrix. A crushing test measures resistance to crushing under compressive forces, indicating how the material will perform under load. Freeze-thaw testing reproduces cycles of wetting and freezing that can crack and spall rocks in cold climates. Mineral hardness reflects inherent toughness and resistance to surface wear. Together, these tests provide a comprehensive view of an aggregate’s ability to stay intact in service, which is why this set is the best choice.

Other options mix tests that don’t directly target aggregate durability or omit key durability factors like chemical and freeze-thaw resistance, so they don’t give a complete picture of stability.