Aggregates. Sand, gravel and crushed rock aggregates for construction purposes / Агрегаты. Песок, гравий и щебень для строительных целей

Aggregates are defined here as particles of rock which, when brought together in a bound or unbound condition, form part or the whole of an engineering or building structure.Natural sand, gravel and crushed rock aggregates are fundamental to the man-made environment and represent a large proportion of the materials used in the construction industry. Re-use of aggregates has become a more common practice and the substitution of natural aggregates by artificial aggregates made from waste products of other industries is a small part of the industry.
Production of aggregates for civil engineering and building construction is one of the world's major industries. Quarrying is the largest industry in terms of tonnage of output (but not value) in the United Kingdom and even in 1985, production was two and a half times that of coal. With the closure of so many deep coal mines in 1999 this figure was nearly seven times larger. <...>