Ferrocrete is a synthetic compound used as a common building material across the human-settled galaxy, especially in bunkers and other Imperial military fortifications. It is composed of a mix of metallic alloys, ceramic polymers and stone of various kinds derived from local sources.
A great many of the standard structures on the worlds of the Imperium of Man are made from ferrocrete because of its high density and ability to stand for thousands of standard years in a wide variety of climates and planetary environments once it sets .
- Imperial Armour - Apocalypse, pg. 29