The concrete shell of this stove would surely crack if its strength were not reinforced with steel rod, wire fabric, or barbed wire. The latter is our choice. We laid continuous strands of barbed wire between the rows of slip form masonry. The thermal expansion rate of concrete is the same as steel up to a temperature comparable to boiling water... Beyond that, steel expands at a faster rate than concrete. At a temperature of about 500 degrees F., the bond between the concrete and steel is destroyed... The type of aggregate in the mix is primarily responsible for this kind of failure.

Ken Kern's Masonry Stove (1983)