Flash-calcined dredging sediment blended cements: effect on cement hydration and properties
Snellings, R.; Horckmans, L.; Van Bunderen, C.; Vandewalle, L.; Cizer, O. (2017). Flash-calcined dredging sediment blended cements: effect on cement hydration and properties. Mater. Struct. 50(6): 241. https://dx.doi.org/10.1617/s11527-017-1108-5
In: Materials and Structures. Springer: Dordrecht. ISSN 1359-5997; e-ISSN 1871-6873, meer
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| Author keywords |
Flash calcination; Clays; Dredging sediments; Blended cement; Hydration;Pozzolan |
| Abstract |
Dredging of docks and waterways generates a large and continuous supply of sediments currently destined for disposal. Transforming this currently wasted materials into new resources still requires meeting technical challenges. One of the options is to process the sediments into a supplementary cementitious material by flash-calcination. This paper describes the effect of cement replacement by flash-calcined dredged sediments on cement hydration and key properties. The hydration kinetics, products and microstructure are studied to explain changes in cement properties such as compressive strength development and workability. The flash-calcined dredging sediments show clear pozzolanic activity which surpasses that of typical coal combustion siliceous fly ash (V, EN 197-1). This is manifested in (1) the rate of compressive strength development, (2) reduced portlandite and (3) increased ettringite and bound water contents. The results show that calcination can transform wasted dredging sediments into a new supplementary cementitious resource for producing large volumes of low-CO2 blended cements. |
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