Road Aggregates

Man has used sand and stone for foundations for thousands of years. Significant refinement of the production and use of aggregate occurred during the Roman Empire, which used aggregate to build its vast network of roads and aqueducts.

Aggregates forms the major part of pavement structure

• All bituminous and concrete surfacing are principally composed of aggregates,they play an important role in the behavior of the pavement surfacing.
• Wood’s definition :- Aggregate is an aggregation of sand,gravel,stone,slag or any other material,in combination with some cementing material attains higher engineering properties and form highway materials like WBM,BM etc.
• Road aggregate, or simply “aggregate”, is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates.
• Aggregates are a component of composite materials such as concrete and asphalt concrete; the aggregate serves as reinforcement to add strength to the overall composite material.
• Aggregates are widely used in drainage applications such as foundation drains, retaining wall drains, and road side edge drains. Aggregates are also used as base material under foundations, roads.

Aggregate Characterization

• Aggregate Physical Properties
• Maximum Aggregate Size
• Gradation
• Other Aggregate Properties
• Toughness and Abrasion Resistance
• Specific Gravity
• Particle Shape and Surface Texture
• Durability and Soundness
• Cleanliness and Deleterious Materials

Aggregate Gradation IS:2386-1963 Part I

Fuller and Thompson’s Equation (Interactive Equation)

Fineness Modulus

Aggregate Crushing Value IS: 2386 (Part IV)

Aggregate Impact Value IS: 2386 (Part IV)

Impact value

BITUMEN ADHESION

Angularity number