Natural alluvial or beach are usually dredged

Gravel and sand are usually dug natural or dredged from a well, river, lake, mountains or the sea floor. Crushed aggregate is produced by crushing quarry rock, boulders, pebbles, or large gravel. Recycled aggregate concrete is a viable source and used effectively in layers of soil-cement and concrete cleaning again. Processing consists of aggregate crushing, screening and washing the aggregate to obtain proper cleanliness and size. If necessary, the technical help asjigging or heavy media separation can be used to improve the quality.

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