MUNICIPAL SOLID WASTE INCINERATION FLY ASH AS SUPPLEMENTARY CEMENTITIOUS MATERIAL

Municipal solid waste incineration (MSWI) generates annually at least 25 Mt of solid residues worldwide. Fly ash represents a smaller part of this amount but its chemical composition necessitates application of a treatment technique in order to prevent an environmental damage before its disposal. The most popular treatment method is cement solidification. On the other hand MSWI fly ash has similar properties as coal fly ash and thus it could be utilize as Supplementary Cementitious Material (SCM). Unfortunately the direct application is impossible due to high content of salts in MSWI fly ash and thus a treatment technique is needed. One of possible ways is extraction of fly ash by water or water solutions. The present paper deals with SCM-related properties of MSWI fly ash from a Czech incinerator; the fly ash was treated by water solutions of different pH. The efficiency of fly ash treatment was evaluated by means of measurement of compressive strength and durability of mortars where the ash was used as SCM.