Use of incinerated sewage sludge ash in cement mortars: case study in Croatia

Abstract

In the paper an experimental research has been carried out regarding the possibility for the use of incinerated sewage sludge ash (ISSA) in the production of cement mortars with partial cement replacement. Different mixtures of cement mortar have been investigated, with comparison of its basic characteristics with and without certain amounts of added ISSA that was incinerated at the temperature of 800 °C. Additionally, the influence of the additives (metakaolin and silicon dust) was also investigated with the purpose to improve the physical characteristics of mortars. Altogether 177 specimens of cement mortar were investigated, with 9 different mixtures. In this research the sewage sludge from the Zagreb wastewater treatment plant was used. Results have shown satisfying physical and mechanical characteristics of mortars with added ISSA (workability, setting time, flexural and compressive strength) which brings to conclusion that use of ISSA in production of cement mortars seems possible and justified.

Keywords

• cement mortar
• incineration
• ISSA
• sewage sludge
• wastewater