rapport 1129 Potentialbedömning av flygaskor ...

VÄRMEFORSK
great interest in the s / s method, not least because it allows utilization of the contaminated
masses and simultaneously reduces the need to use finite resources and reduce the
environmental impact from transport.
Conclusions and Further Investigations
The conclusion is that the project, through conducted laboratory studies, has shown that
there is potential for the use of dry fly ash as a binder component is s/s- projects. The
project has also shown that wet storage of fly ash has a potential as a binder component
in s /s projects. This is especially interesting because thermal power plants do not produce
fly ash from May to October, which means that there will be a need to store fly
ash. Wet storage, however, affects the quality of fly ash, in part through reduced hardening
ability. There is therefore a need to further investigate how wet storage of fly ash
shall be quality assured, and how different properties are affected by wet storage. It
would also be of interest to investigate different methods to activate a wet stored fly
ash.
Generally, high demands and standards are required of geotechnical structures built in
ports, which subsequently means high demands on the quality of the binders used for
stabilisation / solidification. A quality assurance of the binder mixture means that the
binder mixture shall meet the requirements of each individual project, and be sturdy
binder mixture that is capable of meeting variations in
• the fly ash quality,
• the sediment quality,
• the binder amount in the stabilised material (this depends on the choice of the
stabilisation method).
Mixtures of various different fly ashes will often be needed to meet project production
rate, which accentuates the quality and accuracy requirements even more. The need for
large volumes of binders means that binder suppliers must cooperate and that the logistics
needed to ensure delivery of fly ash in an s / s project is a process that requires good
preparation.
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