Aggregate Extraction

Aggregate Extraction UK

When the land masses were young, magma erupted up to the surface of the ground where it hardened to become granite rock.

As the commonest hard rock on earth, its excellent properties make it a popular building material. It contains granular crystals of mica, quartz etc. and some samples when polished can be used for decorative purposes.

In the main it used in general construction terms.

This hard rock, when crushed is used as granite aggregate and is the best aggregate in making high- grade concrete. It is one of the standard aggregates along with sand gravel and limestone that are extracted today, and are fundamental to the construction industry.

Gravel is usually a naturally occurring resource, made up of rock fragments which have been produced by natural erosion by water, and current and former river beds sea reaches or lake bottoms and wherever coarse sediment has been laid down for a long time.

Areas of south and eastern England are particularly rich in gravel, it having been deposited by retreating glaciers of the ice age.

Extraction of aggregates is carried out by means of open case mining using suitable wheeled loader machines to dig the materials and load lorries.

Sand is also a product of the erosion of rocks and is an important bulker and binder in construction. Found in many UK areas, its value to bulk ratio, means that transporting it far is uneconomical, and areas, no matter small, of potential sand extraction can be utilised or mothballed as demand requires.

Sharp sand is preferred in concrete and road construction and is a coarser sand, produced by (in geophysical terms) relatively recent erosion, usually of hard granite type-rock leaving angular grains.

It is a “general purpose” aggregate and is used throughout the construction industry and in the manufacturing of concrete blocks, bricks and pipes.

This compares with soft sand, usually, (in geophysical terms) older and eroded to fine rounded grains which for example, in a dry desert situation, would blow about, constantly smoothing grain against grain.

This type of sand is preferred by builders for use in brick laying allowing for a smoother and more malleable mortar mix. It is also preferred for things like bunkers on golf courses, arena floors or playgrounds.

Limestone aggregate is the other major ingredient along with sand, gravel and granite, used in road building and in the manufacture of reinforced concrete products.

It is produced by crushing sedimentary rocks which have a high content of calcium carbonate.

As a result of recycling of construction waste, secondary aggregates are produced from crushing bricks, concrete and asphalt.

This is very economical compared to mining, and produces a low grade but useful product. It is used as a bulk filler for concretes, and general bulk filler in road and building construction.