Abstract

The chemical and physical characteristics of five different fly ashes originating from fluidized bed combustion of peat, wood, or different wastes were investigated to determine whether they fulfilled the requirements for concrete set by the European EN 450-1 standard. Fly ash originating mostly from peat combustion fulfilled all the requirements of the EN 450-1 standard, without any treatments. Some chemical and physical characteristics (i.e., free calcium oxide, sulfate, chloride, and fineness) of the other types of fly ash exceeded the limits in standard, and the sum of the main components (SiO₂, Al₂O₃, and Fe₂O₃) failed to comply with the standard. However, it should be noted that the requirements of the European standard are more restrictive than similar standards in the US; all applications are not needing standardized concrete, and the potential utility of the studied fly ash materials could be improved by mechanical treatments.