Aggregate

Summary

Aggregate - A relatively inert, granular material used in construction.

Technical Information

Aggregate is the most mined material in the world and can consist of sand, gravel, crushed stone, slag or recycled aggregate.

Aggregates have the following applications in industrial concrete flooring:

As a constituent of concrete – Because aggregate is much cheaper than cement, it is economical to use as much aggregate as possible for a given volume of concrete. The extent to which this can be done varies depending on the required strength of the concrete. It also provides the concrete with most of its compressive strength.
As the main constituent of a sub-base – Aggregate is the main constituent of a sub-base and is used mainly because its behaviour is much more predictable than that of clay and the grading of its particles can be easily controlled.

In concrete construction, it is important that aggregate has the right moisture levels. If it is anything less than saturated internally, it will ‘steal’ water from the paste, leading to workability issues. If it is saturated and has excess moisture on the outside, it will add water to the paste, causing the strength of the hardened concrete to decrease. If the moisture levels in the aggregate cannot be controlled, it may be necessary to adjust the amount of water added to the concrete mix.