The artificial volcano on Stein Island was built in 1788–1794 as part of “Gartenreich Dessau-Wörlitz”, today a World Heritage Site. In order to protect the volcano masonry from the temperature caused by the fire, earth blocks were added to the inside of the walls. ZRS Ingenieure analyzed the condition of the existing masonry and assessed the protective effect as realistic and durable.
The addition was designed as a lightweight earth block inner shell. The straw aggregate in the earthen material has a crack-preventing effect in the early stages of the fire, then glows out and the remaining voids have a strong temperature-minimizing effect. The inner shell was built with 1200 Claytec earth blocks from Pfennig-Bau in Oschatz. After a test eruption and two official eruptions of the artificial volcano, the surface of the inner shell of the earth block was slightly encrusted, but remained undamaged. The desired temperature reduction for the existing masonry had been measured previously, but was greater than expected.
