Ash from the incineration of municipal waste as a component of cement mortars with a low water-to-cement ratio

The growing volume of waste and the lack of landfill space are becoming an increasingly serious problem for waste management. New regulations stipulate that from 2035, only 10% of municipal waste may be landfilled. Consequently, methods of municipal waste disposal other than landfilling must be sought. One such method is the thermal treatment of municipal waste, which is becoming increasingly popular in many countries around the world. This process produces by-products such as ash and slag from the incineration of municipal waste. The management of these by-products poses a significant challenge. They are difficult to utilize due to their variable chemical composition, which depends on the waste incineration plant and its location. This study investigated the possibility of using waste incineration ash as a cement substitute in cement mortar. The municipal waste incineration ash originates from the municipal waste incineration plant in Poznań.

The basic properties of cement mortars were investigated: consistency, density, water absorption and compressive strength. These properties were tested for a reference sample and for samples containing municipal waste incineration ash as a cement substitute. The ash was substituted for cement in amounts of 10%, 15% and 20%. CEM I 42.5R cement, water and 0.5–2.0 mm quartz sand was used for the mortars. The cement mortars were prepared in accordance with standard PN-EN 196-1.

Analysis of the results showed that an increase in compressive strength was observed for mortars containing 10% and 15% ash, compared with the reference sample. In contrast, a decrease in compressive strength was observed for the mortar containing 20% ash.

In conclusion, research into the use of municipal waste incineration ash in cement mortars should be continued. The compressive strength results demonstrate the positive effect of the ash on the cement mortar. Further studies should include a chemical analysis and an assessment of the heavy metal content in mortars containing this additive.