Refractory Concrete

concrete capable of retaining its physicomechanical properties within predetermined limits during prolonged exposure to high temperatures. Binders used in refractory concrete include portland cement; slag-portland cement; high-alumina, alumina, or periclase cement; water glass; and phosphate bonds. Finely divided additives are added to the binders in many cases. Crushed heat-resistant or refractory rocks, chips of fired heat-resistant products, and some other materials are used as fillers. According to the degree of fire resistance, refractory concrete is subdivided into highly refractory (fire resistance above 1770°C), refractory (1580°- 1770°C), and heat-resistant (below 1580°C) varieties. Refractory concrete is used in the construction of thermal units and the foundations of industrial furnaces and other structures subjected to prolonged heating.