Performance of concrete mixtures containing MSWI bottom ash

Abstract

In the European Union, each inhabitant annually generates about 500 kg of municipal waste. About 30 % of this are incinerated in waste-to-energy plants. It results in approximately 20 million tonnes of residues known as municipal solid waste incinerator (MSWI) bottom ash, which is typically landfilled. To address the continuous growth of landfills and to implement zero waste and circular economy policies, researchers are focusing on possibilities to use MSWI bottom ash in civil engineering instead of landfilling. One of them is to replace natural aggregates in concrete mixtures applicable for roads with MSWI bottom ash. Therefore, the subject of this research is the performance of concrete mixtures containing different amount (0–100%) and fraction (0/5–0/16) of MSWI bottom ash. Four specimens with similar aggregate gradations were designed. Each of them was mixed with two different amount (340 kg/m3 and 300 kg/m3) of cement (CEM I 42.5 R). In total eight different concrete mixtures were tested and analysed. The performance of designed concrete mixtures containing different amount of MSWI bottom ash was evaluated according to density and compressive strength after 28 days. The results showed good MSWI bottom ash performance as a substitute for natural aggregates. The compressive strength after 28 days varied from 21 MPa to 29 MPa depending on the aggregate type and amount of MSWI bottom ash and cement. For concrete mixtures made only of MSWI bottom ash at least 340 kg/m3 of cement is required to achieve compressive strength higher than 20 MPa.