Raw compact (3) comprising a binding phase of one or more powdered binding agents, which raw compact has the capacity, following saturation with a liquid reacting with binding agents, to form a chemically bound ceramic material, and which raw compact preferably has a degree of compactness of 55-67 percent by volume solid phase. According to the invention, the raw compact (3) also comprises one or more expansion-compensating additives adapted to give the material dimensionally stable long-term properties. The invention also relates to a method of manufacture of the ceramic material, and a compaction device and a compaction body for compacting the saturated raw compacts.