Natural aggregates

The general term ‘natural aggregates’ refers to the granular materials obtained by crushing natural stones or natural alluvial deposits from the sea and elsewhere (mainly solid stones) and/or by sieving.

Based on the desired use, we distinguish three major categories of natural aggregates, each of which has its own field of application: fine, coarse and all-in aggregates.

Fine and coarse aggregates are commonly used as raw materials in the production of:

• ready-to-use concrete for road construction (roads, bicycle paths, car parks ...), for linear prefabricated concrete elements (curbs, gutters, partitions, sewer pipes ...), for civil engineering structures (concrete bridges, buildings, tiles ...) ...
• bituminous mixtures for road construction (roads, cycle paths, car parks ...) ...

All-in aggregates are generally used as pavement in road construction (sub-foundation, connected and unconnected foundations ...).

• COPRO takes random samples of aggregates at the production unit.
• It oversees the laboratory responsible for the manufacturer’s factory production control.
• It checks the results obtained by the manufacturer as part of factory production control.

• The delivery note indicates a specific code for the aggregate based on its intrinsic and production characteristics.
• The delivery note mentions PTV 411, the BENOR logo and the unique number of the production unit.
• The list of the certified products of each production unit can be consulted at www.procertus.be.

• The producer regularly checks the characteristics of the aggregate, thus continuously guaranteeing correspondence with the certified code.
• Thanks to this factory production control, which is periodically monitored by an accredited external inspection body such as COPRO, possible deviations or defects are limited as much as possible (reproducibility of the results, compliance with the standards by the factory production control lab, and the methods used in the internal test ...).

A good natural aggregate contributes to controlling the applications in which it is used because its certified properties are constant. Good control in turn improves the quality of the finished products in which it is used. Moreover, the aggregate’s code is often stated in the specifications for each possible application. Thus it helps in choosing the right aggregate.

You can find the technical documents and certification documents here.