Construction of new buildings and infrastructure impacts the environment and the sustainability of the construction industry. The environmental impact can be reduced by using fewer materials during the construction phase, manufacturing cementitious materials, e.g. concrete, with less cement, and, replacing Portland clinker with secondary cementitious materials (SCM). Portland clinker has already been partially replaced by SCMs to great effect, however, limited availability of traditional SCMs necessitates the identification of new resources.
Fly ash from municipal solid waste incineration (MSWI) has been proposed as a potential resource for several different applications, including as an SCM. MSWI fly ash is classified as a hazardous waste material due to its toxic metal content and remains unused and is currently disposed of at hazardous disposal sites. The pH in Portland cement-based materials results in chemical binding of toxic metals, reducing short term leaching. However, this chemical binding does not account for later changes to the cement-based materials, necessitating treating the MSWI fly ash and reducing its toxicity before use as SCM.
The main objective of the PhD project is to treat MSWI fly ash using electrodialytic remediation to reduce the toxic metal content of the ash and test the usability of the treated fly ash as an SCM in cement-based materials, identifying problems and possibilities.
The project is made in collaboration with Nordic Five tech alliance Partners, with co-supervisors from Chalmers University (Chalmers), Sweden and Norwegian University of Science and Technology (NTNU), Norway.
Supervisors: Gunvor M. Kirkelund (DTU Byg), Britt-Marie Steenari (Chalmers), Mette R. Geiker (NTNU)