Municipal solid waste incineration fly ash stabilization and immovilization into sulfoaluminate cement mortars: physical/mechanical behaviour

The first objective of the research aims to transform the waste formed mainly by calcium hydroxide and calcium hydroxychloride into another limy type material (calcium carbonate material). This is achieved by transforming the high soluble heavy metals chlorides into low soluble carbonates. The second objective focuses on the stabilization and use of this MSWI fly ash as part of the aggregates used in the production of cement mortars. Previous studies emphasize that the mechanical strength of mortars elaborated with Portland cements and the incorporation of fly ash as a partial substitute for the aggregate were significantly affected when compared to the reference mortars. On the contrary,the use of sulfoaluminate cements (CSA) has been demonstrated to be a highly effective way to safely encapsulate hazardous materials without affecting mechanical strength. In addition, CSA was also chosen due to the perception that sulphur content would make the precipitation of heavy metals in the form of sulphides easier