Influence of fly ash from the thermal treatment of municipal sewage sludge on chosen properties of hardening slurries

Over recent years in Poland, there has been a rapid accumulation of sewage sludge – a by-product of the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. The aim of this experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. The article presents the technological and functional parameters of hardening slurries with the addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analysed on the basis of their basic properties. The mandated requirements for slurries employed in the construction of cut-off walls in flood embankments are listed as a criterion of usefulness. On the basis of this experiment, the usefulness of fly ash obtained through SSTT as an addition to hardening slurries was identified.