Incinerator ashes are ashes
from energy-from-waste recovery. They are available in two forms:
• Incinerator bottom ash
aggregate (IBAA) is a granular material that can be used as
a partial replacement of natural aggregate (normally up to a
maximum of 25% by mass) in new low-strength concrete.
•Incinerator fly ash (IFA) is a powder-like material that
can be used to promote the reaction between fly ash and Portland
cement.
600,000 tonnes of IBAA and
70,000 tonnes of IFA created from incineration of municipalsolid
waste are produced in the UK each year. The vast majority of
this is currently sentto landfill. Whilst their use in concrete
will have only a small impact on the 165 milliontonnes of natural
aggregate and 15 million tonnes of Portland cement used each
year,they can be used to prevent higher-value materials being
used inappropriately in lowvalueapplications.
Use of incinerator ashes in concrete will contribute
towards sustainable development by:
•using a material that would otherwise
be sent to landfill
•reducing overall greenhouse emissions
•reducing natural aggregate usage
•potential reduction in transport impacts.
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