Aggregates are very common in many applications, including the building of houses, use as a base layer for asphalt-paved roads, and in concrete and asphalt manufacturing technologies. Aggregates are an excellent decoration for yards and gardens. Fine gravel is a perfect substratum for many rock flowers and provides very effective protection against the growth of weeds among plants. What is the average knowledge of aggregate types? We are afraid it is rather scarce. Nobody thinks about how they have originated and where they come from.
We most often divide aggregates into natural and artificially produced; other division criteria include their size and origin.
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Construction aggregates:
These are used in the building industry – construction aggregates are characterised by very high compression strength and resistance against abrasion and other mechanical impacts.
Depending on their use, aggregates have to meet a number of standards and requirements, which gives the guarantee for the long life of building structures, constructed on aggregates bases, and ensures their safe use.

Road-construction aggregates:
Aggregates which are used for road construction, road-construction aggregates, have to comply with a number of standards and be characterised by a specific strength and friction coefficient.
Granites, basalts and porphyries, i.e. aggregates of the highest resistance to all outdoor factors and atmospheric conditions, are most often used in the road building industry.

Aggregate application::
In concrete production, similarly as in asphalt production, the main selection criterion is mechanical strength. Therefore, granite and basalt are used for the production of concrete with very high overload strength, while limestone and dolomite are used for the production of such concretes which demonstrate high mechanical strength with regards to load. However, their resistance may be slightly lower. Concrete covers, made of baryte, limonite, goethite and haematite, are another type of concrete, made of high strength aggregates.
The selection of the proper aggregate is of key importance in the building industry, since rocks are characterised by various degrees of mechanical strength and elasticity, which is of the utmost importance for the later use and functionality of the objects raised with aggregate application. In horticulture, both professional and in small home gardens, the aggregate selection criteria are most often based on the taste and the pocket of aggregate owners, since aggregate layers in such applications need not conform to any functional demands, except aesthetic requirements. Thus, nobody thinks about their hardness, elasticity or strength. Thus, the colour and thickness of grains are mainly taken into account.
The thicker the grains, the higher the price. A splendid example of aggregate use in yards are aggregate surface layers on driveways and garden paths, improving their drainage and irrigation features. Rainwater does not accumulate on the aggregate’s surface, thus eliminating mud formation; even after heavy rains, water permeates through the aggregate and soaks into the soil.