Aggregates are fragments of rock measuring from 0.08 to 80 millimeters in diameter. Examples of their uses include:
- road and highway surfaces,
- railway ballast,
- fill material,
- sand traps in golf courses, beaches, playing field surfaces, horse racing tracks, etc.
They can also be mixed with a binder - either cement to make concrete or tar to make asphalt - and used in the manufacture of houses, structures and bridges.
They have 3 main functions:
- support, thanks to their strength. Research into high-performance concrete and bituminous concrete has shown that the strength limits of materials depend, in part, on the aggregates they contain. Aggregates make a vital contribution to the strength of materials.
- filling: aggregates make mixtures more compact, facilitating specific applications including drainage, weatherproofing and heat retention.
- embellishment, thanks to their aesthetic qualities. Sand gives surface treatments their brightness. Local chippings lend their specific colors to many different types of concrete and concrete products, including tinted and stained concrete, interlocking concrete paving, industrialized concrete slabs and panels, and road paving.