Salt-concrete (or ''salzbeton'') is a

building material Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand, wood, and even twigs and leaves, have been used to construct buildings and other structures, like bridges. Apart from natur ...

that is used to reduce the water inflow in

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

shafts in salt mines. It is composed of 16%

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...

, 39%

halite Halite ( ), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...

, 16%

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

powder, 14%

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

and 15% sand.

History

Salt-concrete was used for the first time in 1984 in the potash mine in Rocanville in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

. A salt-concrete seal was also installed in the Asse II mine in

Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...

in 1995.

Filling tunnels

Since the end of the

repository for radioactive waste Morsleben The Morsleben Radioactive Waste Repository (German: Endlager für radioaktive Abfälle Morsleben-ERAM) is a deep geological repository for radioactive waste in the Bartensleben rock salt mine in Morsleben, Landkreis Börde, Börde District, in the ...

in 1998, the

salt dome A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered us ...

stability deteriorated to a state where it could collapse. Since 2003, a volume of m³ of salt-concrete has been pumped into the pit to temporarily stabilize the upper levels. In addition another m³ of salt-concrete will be used to temporarily stabilize the lower levels.

References

{{reflist Cement Concrete Salts Underground mining

History

Filling tunnels

See also

References