Weathered bottom ash from municipal solid waste incineration: Alkaline activation for sustainable binders

Alex Maldonado-Alameda, Jessica Giro-Paloma, Fernanda Andreola, Luisa Barbieri, Josep. M. Chimenos, Isabella Lancellotti

https://doi.org/10.1016/j.conbuildmat.2022.126983

Construction and Building Materials, 2022, 327, 126983

Quartile Q1, Impact 6.141

Alkali-activated binders (AABs) stands out as promising candidates to replace ordinary Portland cement (OPC) since they allow the use of residues as raw material for their manufacture. This investigation addresses the environmental feasibility of using the least polluted fraction of weathered bottom ash (WBA) from municipal solid waste incineration (MSWI) and metakaolin (MK) as alkali-activated binder precursors (AA-WBA/MK).

Different proportions of WBA and MK were mixed (100/0, 75/25, 50/50, 25/75, and 0/100 wt. %) with a mixture of waterglass (WG) and NaOH 8 M as an alkaline activator solution. The effect of the MK content increase was assessed from a chemical, physical, mechanical, and environmental point of view. The results revealed the formation of typical reaction products from C-(A)-S-H, (C,N)-A-S-H, and N-A-S-H gels. It was also showed the influence of increasing MK content in AA-WBA/MK binders’ porosity, which affected the compressive strength. Besides, the AA-WBA/MK binders have been validated from an environmental point of view, although with some restrictions at the end of their useful life.

Funding

This work has been partially funded by the Spanish government (BIA2017-83912-C2-1-R, MINECO/FEDER) and the research Grant FI-DGR 2017 (AGAUR).

Research category: Construction

Projects associated: BIA2017-83912-C2-1-R

Doctoral Thesis: Alkali-activated cement binders based on weathered bottom ash from municipal solid waste incineration