Municipal Solid Waste Bottom Ash as Portland Cement Concrete Ingredient

The disposal of municipal solid waste ash has become a significant economic and environmental issue. Municipal solid waste ash can be considered to have a fly ash and a bottom ash component. Municipal solid waste bottom ash (MSWBA) from a refuse-derived fuel facility was evaluated as a potential portland cement concrete ingredient. Portland cement–related ASTM methods and other analytical techniques such as X-ray diffraction were used. The sample MSWBA was found to be a marginal concrete aggregate. The sample MSWBA met most ASTM C 331 standards such as size gradation, but the high angularity and brittle nature of the MSWBA would significantly affect concrete workability. The MSWBA sulfate and chloride concentrations also were high enough to create potential sulfate attack and reinforcing steel corrosion problems. Iron removal and aggregate processes such as size control offer cost effective methods to improve MSWBA for use as an aggregate.