mineralaggregate

Mineral aggregate refers to inert granular materials used in construction as fillers and structural constituents in concrete, asphalt, and related composites. It is composed of rock particles and mineral fragments and excludes binders such as cement or bitumen. Aggregates can be natural (sand, gravel, crushed stone) or manufactured (crushed rock, slag, manufactured sand) and may include recycled materials. They are categorized by size into fine (generally less than 4.75 mm) and coarse (greater than 4.75 mm).

The properties of mineral aggregate are governed by particle size distribution (grading), hardness, soundness, porosity, and resistance to weathering and different chemical exposures. They must be clean and free of deleterious substances such as clay, silt, organic matter, or salts that could impair bonding or durability. Standard tests measure density, moisture content, abrasion resistance, and aggregate crushing value.

Production involves mining or quarrying, crushing and screening to achieve the desired grading, and sometimes washing to remove fines and contaminants. For recycled aggregates, processing includes crushing, screening, and quality control to ensure performance criteria are met.

Uses include concrete production (as coarse or fine aggregate), asphalt pavement mixtures, road base and subbase layers, drainage blankets, and foundational fills. The choice of aggregate depends on strength, durability, workability, and local availability, as well as environmental and economic considerations. Standards and guidelines in different regions define acceptable grades, quality, and testing methods to ensure consistent performance.