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Effects of the Incorporation of Municipal Solid Waste Incineration Fly Ash in Cement Pastes and Mortars. Part 1: Experimental Study.


pdf icon Effects of the Incorporation of Municipal Solid Waste Incineration Fly Ash in Cement Pastes and Mortars. Part 1: Experimental Study. (1373 K)
Remond, S.; Pimienta, P.; Bentz, D. P.

Cement and Concrete Research, Vol. 32, No. 2, 303-311, 2002.

Keywords:

solid waste; fly ash; cement paste; mortar; cements; hydration; microstructure; waste materials

Abstract:

This work falls within the scope of a general problem regarding the assessment of concretes manufactured from waste materials. The main objective is to study the long-term evolution of these materials during the leaching process, using the cellular automata based hydration model developed at the National Institute of Standards and Technology. The work is based on the analysis of mortars and cement pastes containing experimental waste: Municipal Solid Waste Incineration fly ash (MSWI fly ash). The study therefore aims to develop a methodology for assessing concretes manufactured from waste, and not to study a process or a formulation enabling the incorporation of the waste in concrete. The physical, chemical, and mineralogical characteristics of MSWI fly ash were first analyzed to introduce them into the model. A simplified quantitative mineralogical composition of the ash was proposed. The performance characteristics for mortars containing ash were then studied. This study showed that the soluble fraction of the ash, in particular chloride, had a significant influence on the properties of mortars. The hydration products that form in cement pastes in the presence of ash were then examined so as to include the ash/cement interactions in the hydration model. In particular, the ash chlorides modify the hydration reactions of the cement's calcium aluminates.