Properties of calcium enriched fly ash and its utilization in concrete

Properties of Calcium enriched fly ash (CEFA) and its utilization is introduced in this paper. CEFA is combustion residue in electric power plants burning bituminous coal. The calcium is enriched intentionally by means of grinding limestone and coal powder together. CEFA is formed in the turbofurnace of the vertical cyclone boilers at the temperature of 1450 C to 1600 C. CEFA is characterized by higher calcium oxide and free lime lower ferric oxide, lower water requirement, and higher reactivity. Self-setting and self-hardening are the specific performance because of existence of lime, calcium silicates and calcium aluminates in it. In concrete mixture, the volume of fly ash can be as high as 20% to 70% of the binder. Concrete develops a satisfactory compressive strength when cement is partially replaced.