Salt-concrete (or salzbeton) is a building material that is used to reduce the water inflow in mining shafts in salt mines. It is composed of 16% cement, 39% halite, 16% limestone powder, 14% water and 15% sand.
Salt-concrete was used for the first time in 1984 in the potash mine in Rocanville in Canada. A salt-concrete seal was also installed in the Asse II mine in Lower Saxony in 1995.
Since the end of the repository for radioactive waste Morsleben in 1998, the salt dome stability deteriorated to a state where it could collapse. Since 2003, a volume of 480,000 m3 of salt-concrete has been pumped into the pit to temporarily stabilize the upper levels. In addition another 4,000,000 m3 of salt-concrete will be used to temporarily stabilize the lower levels.