Research article2008Peer reviewed
Assessment of Pb-slag, MSWI bottom ash and boiler and fly ash for using as a fine aggregate in cement mortar
Saikia, Nabajyoti; Cornelis, Geert; Mertens, Gilles; Elsen, Jan; Van Balen, Koenraad; Van Gerven, Tom; Vandecasteele, Carlo
Abstract
Three types of wastes, metallurgical slag from Pb production (SLG), the sand-sized (0.1-2mm) fraction of MSWI bottom ash from a grate furnace (SF), and boiler and fly ash from a fluidised bed incinerator (BFA), were characterized and used to replace the fine aggregate during preparation of cement mortar. The chemical and mineralogical behaviour of these wastes along with the reactivities of the wastes with lime and the hydration behaviour of ordinary Portland cement paste with and without these wastes added were evaluated by various chemical and instrumental techniques. The compressive strengths of the cement mortars containing waste as a partial substitution of fine aggregates were also assessed. Finally, leaching studies of the wastes and waste containing cement mortars were conducted. SLG addition does not show any adverse affect during the hydration of cement, or on the compressive strengths behaviours of mortars. Formation of expansive products like ettringite, aluminium hydroxide and H-2 gas due to the reaction of some constituents of BFA and SF with alkali creates some cracks in the paste as well as in the cement mortars, which lower the compressive strength of the cement mortars. However, utilization of all materials in cement-based application significantly improves the leaching behaviour of the majority of the toxic elements compared to the waste as such. (c) 2007 Elsevier B.V. All rights reserved.
Keywords
MSWI ash; Pb-slag; fine aggregate; mineralogy; leaching
Published in
Journal of Hazardous Materials
2008, Volume: 154, number: 1-3, pages: 766-777
Publisher: ELSEVIER SCIENCE BV
UKÄ Subject classification
Other Environmental Engineering
Publication identifier
DOI: https://doi.org/10.1016/j.jhazmat.2007.10.093
Permanent link to this page (URI)
https://res.slu.se/id/publ/80958