Cement Hydration in the Presence of Municipal Solid Waste Incineration Fly Ash.
Cement Hydration in the Presence of Municipal Solid
Waste Incineration Fly Ash.
Remond, S.; Bentz, D. P.; Pimienta, P.; Bournazel, J. P.
Material Science and Concrete Properties, 1st
International Meeting. Proceedings. March 5-6, 1998,
Toulouse, France, 63-70 pp, 1998.
cements; solid waste; fly ash; cement hydration
Incorporating wastes into concrete on an appropriately
selective basis could help to solve some of the problems
encountered in waste management. Some industrial
by-products (fly ash and slag for example) have been
used in the manufacture of cement and concrete for many
years. However, before waste can be used on a large
scale in concrete, the properties of the resulting
concrete need to be studied in order to ensure that the
new material is suitable for use in construction. The
main aim of this research is to develop an approach for
assessing the performance characteristics, environmental
impact and durability of concretes containing wastes. In
this paper we describe the study bearing on the
environmental impact of these materials. This approach
is based on a study of mortars containing an
"experimental" waste, Municipal Solid Waste Incineration
Fly Ash (MSWIFA). These wastes are very heterogeneous
and contain large quantities of heavy metals and soluble
salts which could give rise to problems when
incorporated in concrete. The leaching of toxic
materials from concretes containing wastes may present
health and environmental risks. The quantities released
over a period of time must therefore be determined in
assessing the environmental impact of these concretes.
To predict the quantities of toxic materials released in
actual conditions of use over the long term, models of
leaching from waste-containing concrete need to be
developed. To achieve this, one must understand the
influence of waste on cement hydration, the mechanisms
by which pollutants pass into solution, and the
evolution of the material microstructure during
leaching. The objective of this study is to apply the
CEMHYD3D model developed by Bentz and Garboczi to cement
pastes containing MSWIFA in order to simulate the
hydration of this material and the evolution of its
microstructure during leaching. In this article, we
describe the experimental study undertaken in order to
determine the model input data.